Here is a list of all bosses in Chrono Trigger, and how to beat them. The way to kill them is the one we use, and we think they are the best ones. When you have to beat a boss, we suggest you to wear GoldStuds, so you can attack the boss without having to worry about your MP.
1. Yakra (600 AD, Cathedral) Use X-Strike and Flame Toss on him, stopping to heal yourself with tonics or Frog's Slurp when your HP gets low. He will occasionally counterattack after you attack him. This will hit all members of your party for a decent amount of damage. Beware his needle attack, as it does a lot of damage. Heal right after it. He has 920 hit points, gives 50 experience, 5 tech points, and 600 Gold.
2. Dragon Tank (1000 AD, Guardia Castle) The Dragon Tank has three parts: the Head, the main body, and the Grinder (wheel). The Head repairs damage to the body. It also contains a shield that prevents damage by lightning and fire. Take out the head first if you want to even think about defeating the tank. The head will use a flame attack on you, doing moderate damage. The Grinder will run over you, doing a lot of damage. The Body will either use missiles on you (doing moderate damage) or a laser beam, doing high damage. Destroy the head with your weapons, then attack both the Grinder and the body with Flame Toss and Slash. When your HP gets low, use tonics. The Head has 600 HP. The Grinder has 208 HP. The Body has about 266 HP. For defeating it you get 40 exp., 5 tech points, 500 G.
3. Guardian and Bits (2300 AD, Arris Dome) First, kill off both bits with your weapons. Then concentrate your attack on the main body with your strongest techs. Heal when your HP gets too low, with Aura Beam. The body will regenerate the bits after a time. Repeat the process until you have beaten the body. Each Bit has approximately 200 HP. The Guardian has approximately 1200 HP. For defeating it you get 300 experience, 5 tech points, 1000 G.
4. R Series (2300 AD, Factory Ruins) There are six Robots in all. Your best bet is to use area effect spells to do as much maximum damage as possible. You will only have two people in your party to fight them, so they might be tough if you aren't at a high enough level. Their regular attacks are fairly weak, but they have a few special attacks which are somewhat powerful. They have a version of monster toss, which will hurt both of your people for a decent bit of damage, and when there is only one Robot left, it will use some kind of bomb on you that does a lot of damage. Though Marle might have healed the party, have Lucca with you. Cyclone works well against them, as two cyclones can take out three of them in two attacks, while Lucca makes Flame Tosses on two or three robots at a time, or heals the party with tonics. Each Robot has 150 HP. For beating them, you get 480 Experience, 6 tech points, 600 G.
5. Heckran (1000 AD, Heckran Cave) Magic is the only thing that will hurt him, so wear a MagicScarf. When he says "Go ahead and try to attack me" do not attack him, as he will use a nasty counterattack spell that will do major damage to all of your people. When it says "brief counterattack break" then give him everything you've got: Fire, Ice and Lightning. When he says "Yes Indeed" he will nail one of your characters with a major damage attack. Heal him with Marle. Heckran has approximately 2100 HP. For defeating Heckran, you get 250 experience, 10 tech points, 1500 Gold.
6. Zombor (600 AD, Zenan Bridge) Use Ice Magic or regular attacks on the top section. When the top section dies, it casts MP Buster on you, which will take all of the MP away from the person who killed it. Use Lightning Magic, Fire Magic, or regular attacks on the bottom section. Its' regular attack isn't too bad, but it will sometimes do an earthquake which will hit all of your party for a fair amount of damage. Be sure to heal after that with Marle. The top section has 960 HP The bottom section has about 800 HP. For defeating Zombor, you get 350 experience, 10 tech points, 1500 Gold.
7. Masa and Mune (600 AD, Denadoro Mts.) At first, Masa and Mune seem like innocent children, that is until they turn into monsters and attack you. Your first step is to have Lucca cast Hypno Wave on the two. Now you should attack one of them and make sure the other stays asleep. Attack with your weapons. You only need to defeat one of them to win the battle. They have 1000 HP each. For defeating them, you get 400 experience, 4 tech points, and 400 Gold. Then, it says "Apart, Masa and Mune are powerless." and then you realize the battle is not over. The game says "With Masa's bravery, and Mune's knowledge! Two become one!" Now they turn into big and ugly. Hit this guy with your best attacks and magic. All of his attacks are fairly strong, so beware and keep your HP up with Aura Beam. When it says that he is storing tornado energy, use Crono's Slash attack on him to neutralize it. He may also attack with a Slash attack of his own, doing decent damage to two people in your party. The second form of Masa and Mune has 3600 HP. For defeating him, you get 500 Experience, 10 tech points, 1500 Gold. Masa and Mune then separate, and you get the broken Masamune.
8. Nizbel (65,000,000 BC, Reptite's Lair) As for regular dinosaurs, use Lightning on this guy. Then nail it with everything you have. When it says "releases electrocution energy" he is gonna zap you. This will do an extreme amount of damage, in the upper one hundred range. After that, heal your party with Robo's Heal Beam, for example. You will need to hit him with lightning again. His earthquake attack will do about 40+ points of damage to him. Nizbel has approximately 4200 HP. For defeating him, you get 500 experience, 10 tech points, and no gold or items. If you use Charm on him, you get a Third Eye.
9. Slash (600 AD, Magus' Castle) Like most of the bosses in Magus' Castle, Slash has multiple forms. His first form is rather weak. Use a combination of magic and regular attack on him. His "attack attack attack" move does about 80 points of damage to one character, so make sure your HP is up. You know you have won when he uses an attack that hits the entire party for about 50 damage. The first form has about 3300 HP. He will then grab his sword from the wall, and begin to attack you with his Slash technique. This will hit either one, two, or all three members of your party for about 60 damage. Make sure to heal often with Frog or tonics. His "Yes indeed" attack will do over 100 points of damage to you, and is quite powerful. Heal right after that. Slash has 5200 HP. For defeating Slash, you get 500 experience, 10 tech points, 1500 Gold. You also get the Slasher 1 Sword for winning.
10. Flea (600 AD, Magus' Castle) Flea also has two forms. The first form is rather wimpy however, and doesn't take much to kill. The only real thing it does is steal all of the MP of one of your characters. So make Lucca kill it, since the real Flea is "weak" against weapon attacks, not against Lucca's magic. Then you attack the real Flea. This form is much more powerful than the first. X-Strike works pretty well against it, as well as just regular attacks, and Crono's Spincut works rather well too. Make Lucca use her gun. Flea will use Chaos attacks, Sleep attacks, and Poison attacks against you. Make sure to bring Heals with you to counteract their effects. The Stare will get one of your party to attack the rest of your party, injuring everyone badly. Heal with Frog or tonics to heal the party. Flea has about 4120 HP. For defeating Flea, you get 500 experience, 10 tech points, 1000 Gold and a Magic Tab.
11. Ozzie (600 AD, Magus' Castle) Ozzie puts up a protective barrier so that you can't hurt him. So don't even try to hit him, or he will just counterattack you. Instead, hit the winches that are next to him. This is all you need to do to win the battle. After you've hit them all, Ozzie will fall through the floor, and you will win. For defeating Ozzie, you get nothing.
12. Magus (600 AD, Magus' Castle) Magus is one of the toughest bosses to beat if you don't know what you are doing. You need to pay attention to what magic he is using against you. That is the barrier he has up at the moment. It is best to have a varied party so you can hit him with whatever magic he is using against you: Frog, Crono and Lucca (and if you can manage it, try to have learnt Delta Storm triple tech before). Have Frog attack with the Masamune when Magus's barrier isn't water-magic. This will help lower his defenses, and help prevent him from casting certain spells on you. He will also use Dark Matter, his strongest spell which will do 200+ points of damage to the whole party. There will come a time during the battle when Frog seems to be doing significantly more damage with his attacks. When this happens, hit him with your best physical attacks and/or with Delta Storm, and he will not counterattack. This is a sign that he is weakening. Magus has 6666 HP. For defeating Magus, you get 1500 experience, 15 tech points, 3000 Gold.
13. Nizbel II (65,000,000 BC, Tyrano Lair) Nizbel II is every bit a pain to beat as the original Nizbel. His charge attack will do a fair amount of damage to everyone in your party. Use Lightning on him to decrease his defense. Rock Throw works well against him. Again, he will discharge the lightning energy, and it will do a lot of damage. Heal with Robo's Heal Beam right after it. Nizbel II has approximately 7000 HP. For defeating Nizbel II, you get 880 Experience, and 15 tech points. If you use Charm on him, you get a Third Eye.
14. Black Tyrano and Azala (65,000,000 BC, Tyrano Lair) This is the final showdown in the battle between the cavepeople and the reptites. Your first job is to defeat Azala. Regular attacks, Lightning and Fire magic seem to work well on her. Azala will use several attacks that do moderate damage, while the Tyrano will either shoot fire at you for moderate damage, or "eat" one person for some major damage in the 200 range. Azala has 2700 HP, and when Azala dies, the Azala Break spell will reduce your HP by a small amount. Now, heal your characters with Robo's Heal Beam and wait until it says "Removes def, and is storing pwr." Now attack the Tyrano with your best techs. Cat Attack works very well on it, and Fire and Lightning magic both are ok. Spincut works better than Lightning though. When it counts down to 0, it will blast you with a powerful fire attack. Heal then. It has 10,500 HP. For defeating them, you get 1800 Experience, and 25 tech points. If you use Charm on them, you get a PowerTab and a MagicTab.
15. Golem (12,000 BC, Zeal Palace) This is one of the tougher bosses in the game because of the Iron Orb attack it can do. This will reduce one characters life by half. Since his physical counterattacks are really tough, the best way to defeat him is to use magic on him. Alternate different kinds of spells on it, and he won't have time to attack you. Or, if you must use any kind of physical attack use Rock Throw, as it does major damage to him. But be sure to hit him with any kind of magic (his counterattacks against Fire are quite weak) immediately afterwards. The Golem has 7000 HP. For defeating the Golem, you get 1000 Experience, 35 tech points, 2000 Gold. If you use Charm on it, you get a MagicTab.
16. Sir Krawlie (2300 AD, Sewer System) Although this guy barely counts as a boss, I'm including him in the list. If you go after him earlier in the game, he can be fairly tough to beat. But later in the game, he is just a wimp. Nail him with your best attacks, but watch out for his 1 HP move. Krawlie has 500 HP. For defeating Sir Krawlie, you get 100 Experience, 5 tech points, 500 Gold.
17. Blue Beast, Red Beast, and Mud Imp (12,000 BC, Beast's Nest) These guys have a lot of HP, but aren't too tough. For the Red Beast, use Ice Magic on it. For the Blue Beast, use Fire Magic on it. Beat the tar of the Mud Imp with physical attacks. The Red Beast has 5000 HP. The Blue Beast has 5000 HP. The Mud Imp has 1200 HP. Leave the Imp for last. But if you cannot beat the Mud Imp, it will run away. For defeating them, you get 600 experience, 16 tech points, 1600 gold. But if you manage to get them all, you get 954 experience, 26 tech points, 2600 Gold. If you use Charm on them, you get a SpeedTab, a MermaidCap and an Elixir.
18. Giga Gaia (12,000 BC, Mt. Woe) The secret to beating Giga Gaia is defeating the hands. Once you defeat the hands, you have a clear opportunity to beat the tar out of the main body before it regenerates the hands. When it has its hands though, it will use dual attacks on you. It will attack you with Shadow and Fire magic, so if you have the colored armors, now is the time to use them. It is best to have your party wear a Black Mail, a Red Mail, and a Red Vest. That way, someone is always being healed by the attacks, and you don't have to worry much about your HP for the battle. Delta Force works very nicely against Giga Gaia, but if you can manage to have these techs, use Luminaire, Flare and Shock. Each hand has approximately 2000 HP. The main body has 9500 HP. For defeating Giga Gaia, you get 3000 Experience, 30 tech points, 3000 Gold. If you use Charm on the body, you get a SpeedTab.
19. Dalton (12,000 BC, Zeal Palace) Dalton will use the Iron Orb attack, which will drop your HP by half. Heal then. Nail this guy with your best magic attacks, and he is fairly easy to beat. He has 3500 HP. When you defeat him, he will use a weird attack that will damage the entire party. For defeating him, you get 1000 Experience, 30 tech points, 2500 Gold. If you use Charm on him, you get a PowerMeal.
20. Golem Twins (12,000 BC, Ocean Palace) These guys can be tough. They are similar to regular Golems, but having two of them makes things even tougher. You should have Luminaire and Flare by now, so use that on them. If you need, heal with Robo's Heal Beam or tonics. It works rather well. Each Golem has 10,000 HP. For defeating them, you get 2000 Experience, 70 tech points, 4000 Gold. If you use Charm on them, you get 2 MagicTabs.
21. Lavos (12,000 BC, Ocean Palace) Although you aren't supposed to win the battle against Lavos, I'm counting it as a boss, as you can kill it by using the New Game Plus. You will fight the outer core, and it will be much more powerful than fighting it at the end of the game like normal. The attacks will do more damage to you, and will be done more frequently. His "Destruction rains from the Heavens!" attack is really powerful. Heal with Robo right after each of these. You should be able to kill it with Luminaire, Flare and Shock. When you defeat the outer shell, you can refer to the end of this document for the Inner Core of Lavos. The outer Shell should have about 10,000 HP.
22. Golem Boss (12,000 BC, Blackbird) This guy isn't that tough. He doesn't attack you at all. He is afraid of heights, so if you can't beat him on your own, he'll run away after a while. The Golem Boss has 15,000 HP. For defeating him, you get 2500 Experience, 40 tech points, 2000 Gold.
23. Dalton Plus (12,000 BC, Blackbird) It's time to finish the fight with this "king". He will use the Iron Orb attack on you, and a weaker form of the Golem's physical attack also. Dalton has 3500 HP. For defeating Dalton, you get 2500 Experience, 40 tech points, 2000 Gold. If you use Charm on him, you get a PowerMeal.
24. Lavos Spawn (2300 AD, Death Peak) The spawn has two parts to it - a "head" and a "body". Attack the head, or else you won't do any damage to it. Magic and physical attacks work best. But try to avoid hitting the outer shell, or else it will use the needle attack on you. Use Frog's Leap Slash, Robo's Uzzi Punch and Ayla's Triple Kick. It has 4000 HP. There are a total of three of these on Death Peak. For defeating the Lavos Spawn, you get 747 experience points, 120 tech points, 500 Gold and an Elixir.
25. Son of Sun (2300 AD, Sun Palace) There is a very easy way to defeat this boss. First, you need the right armor. The Red Mail, the Red Vest, and the Ruby Armor are a must. Don't even think about it without them. If you have Magus, have him cast Black Hole on it, and two of the flames will disappear. After that, cast any level 2 spell, and see which flame does not counterattack. Now hit that flame. When it does the roulette, just cast another level 2 spell on it. Do not bother to try to attack the center, as you cannot hurt it that way. Whenever you hit the correct flame, the center will take about 215 damage no matter how much or little you do to the outer flame. The Son of Sun has about 2100 HP. For defeating the Son of Sun, you get 3800 experience, 40 tech points, 2000 Gold. If you use Charm on it, you get a Black Mail.
26. Flea Plus (600 AD, Ozzie's Fort) This version of Flea is no different from the original version of Flea. In fact, she is weaker than the first version of Flea you fought. Flea has less than 3000 HP. Just bash her with whatever your favorite technique is. He doesn't put up much of a fight. For defeating her, you get 2000 experience points, 20 tech points, 2000 Gold.
27. Super Slash (600 AD, Ozzie's Fort) This version of Slash is not much different from his other version either. Bash Slash with your favorite technique, or weapons. He has about 2500 HP. For defeating him, you get 2000 Experience, 20 tech points, 2000 gold.
28. Great Ozzie, Super Slash and Flea Plus (600 AD, Ozzie's Fort) Try to concentrate on one person at a time, and watch out for their triple tech, as it can be quite nasty. The best way is to attack the Great Ozzie himself with single techniques like Triple Kick, Uzzi Punch, Confuse, Mega Bomb... so there's only one counterattack each time you attack. When he dies, the others die, too. Super Slash has 4000 HP, Flea Plus has 4000 HP, and Great Ozzie has 6000 HP. For defeating just Slash and Ozzie, you get 5000 experience, 50 tech points, 3000 Gold. For defeating them all, you get 7500 Experience, 80 tech points, 4000 Gold. If you use Charm on them, you get an Ozzie Pants, a Slasher 2 and a Flea Vest.
29. Great Ozzie (600 AD, Ozzie's Fort) This is the last stand of Ozzie. He's a wimp as usual. Just attack the level near him, and this time, you will fall down the hole. Go back up, and he will pretty much defeat himself. Since you don't actually defeat him, you don't get anything for your battle. If you use Charm on him, you get a second Ozzie Pants.
30. Rust Tyrano (600 AD, Giant's Claw) This guy is just like the first Tyrano you fought, only stronger. Again, Red Mail, Red Vest, and Ruby Armor are a must if you want to survive the battle. Also, bring Ayla to steal from the boss if you can. This guy can take a lot of damage, so be ready for a long battle. Luminaire is a good spell to have, as well as Flare and Triple Kick. Again, he will count down from 5 and blast you with Fire Magic. This guy is not meant to be tough, but he does have a lot of HP. In fact, the Rust Tyrano has 25,000 HP. For defeating the Rust Tyrano, you get 3800 Experience, 40 Tech points, and 2000 Gold. You can get the Rainbow Shell after you defeat it. If you use Charm on it, you get a Red Mail.
31. Yakra XIII (1000 AD, Guardia Castle) This guy is a lot like his predecessor. He does use chaos a lot, so be prepared if you can. Blast him with your best stuff. Have Marle, Lucca and Ayla. Charm him to get a White Mail, and then attack him with Antipode 3 and Triple Kick. Yakra has a earthquake attack that will do a decent amount of damage to you. The Needle 13 attack will do a lot of damage to you. When you beat him, he will hit you with one more needle attack. Yakra XIII has 18,000 HP. For defeating Yakra, you get 3500 Experience, 40 tech points, 2000 Gold, and 1 MegaElixir. If you use Charm on him, you get a White Mail.
32. Retinite (600 AD, Sunken Desert) Retinite bears a strong resemblance to Zombor, but looks are about all they have in common. In order to defeat this monster, you need to have someone who can use Water or Ice magic in your party. Every time you hit Retinite, it will raise its' defenses against attack, and water will weaken it. We usually attack the mid section first. Magic will not work on Retinite at all. You need to use your best physical attacks on Retinite. Weaken him with Marle's Ice 2, and then attack with Ayla's Triple Kick, and Crono's Confuse. If you need, heal them all with Aura Beam. The Mid section has about 2000 HP. The top section has about 5,000 HP. The bottom section has between 5,000 and 6,000 HP. For defeating Retinite, you will get 2600 experience, 100 tech points, 2000 gold. If you use Charm on the eye, you get a SpeedTab.
33. Atropos XR (2300 AD, Geno Dome) This is a one on one battle between Atropos XR and Robo. Make sure he is powerful enough to stand up to the task at hand. Atropos has the same moves as Robo can do. She will use Area Bomb and Rocket Punch the most, and will also use the Heal Beam on herself. Area Bomb works good against her. Make sure Robo has the highest magic he can have, as he will need the added boost to win. Once you do enough damage to defeat her, it will take a few moments for her to realize that she is dead and will keep attacking you for a bit. Atropos has 6000 HP. For defeating Atropos XR, you get no experience, no tech points, no gold. But you do get Atropos' Ribbon, which will raise Robo's Speed by 3, and Magic Defense by 10.
34. Mother Brain and Display (2300 AD, Geno Dome) This is the psycho robot in charge of the factory. Shutting her down will shut down the place. The displays around the room will heal her. Don't destroy them. If you destroy all three of them, Mother Brain will use her most powerful attacks on you. If you keep one alive, it will still heal her, but she won't be able to use her most powerful attacks. So use Robo's Uzzi Punch, Ayla's Triple Kick and Crono's Confuse. Each display has 1 HP. Mother Brain has 5000 HP. For defeating the Mother Brain, you get 3000 experience, 40 tech points, 3000 Gold. You also get the Terra Arm and the Crisis Arm. Once you win, you cannot re-enter the factory. If you use Charm on them, you get a Blue Mail and Elixirs.
35. Mega Mutant (Black Omen) This sure doesn't look like the Mutants you are used to seeing! Blast this dude with your best techs, Luminaire, Flare and Shock/Dark Matter. It will go down pretty easily. It will use Chaos spells on you, so be prepared for them. You only need to kill either the top or the bottom to destroy it. The top has 3,850 HP. The bottom has 4,600 HP. For defeating the Mega Mutant, you get 900 experience, 50 tech points, 1500 Gold. If you use Charm on it, you get an Elixir and a Vigil Hat.
36. Giga Mutant (Black Omen) This boss isn't much harder than the Mega Mutant. Physical attacks do little damage to it, so blast it with magic. Every time you hit it, it will try to steal some life away from you. It also has a life shaver attack where it reduces your HP to 1 for one person. Heal after that. The Giga Mutant has 4,950 HP for the bottom section. The top section has 5,800 HP. For defeating the Giga Mutant, you get 1500 experience, 80 tech points, 2000 Gold. If you use Charm on it, you get a Hit Ring and a Wall Ring.
37. Terra Mutant (Black Omen) This boss isn't that tough. Magic will tend to heal the lower half, so concentrate on killing the upper half first. The top half has 7,860 HP. The lower half will die when the upper half dies. The lower half has 20,000 HP. For defeating the Terra Mutant, you get 2000 Experience, 100 tech points, 3800 Gold. If you use Charm on it, you get a Muscle Ring and a PowerSeal.
38. Lavos Spawn (Black Omen) This Spawn is very tough to beat. Hit the head only, or it will counterattack you for severe damage. It has a needle attack that will also cause confusion as well as do high damage. It can cast Dark Bomb as well. Use Confuse, Uzzi Punch, Triple Kick... The Lavos Spawn has 10,000 HP. For defeating the Lavos Spawn, you get 2450 Experience, 120 tech points, 2500 Gold. If you use Charm on it, you get a Safe Helm and a Haste Helm.
39. Queen Zeal (Black Omen) This is your first of two battles with the Queen. We suggest to have at least Robo in your party, for he can cure the party with Heal Beams. Her opening attack will be to reduce the HP of your party to 1. But don't worry: she can't kill you. Nail her with cheap magic attacks after this move (to save your MP for later), and if you have them in your party, with Frog's Frog Squash and Ayla's Dino Tail. These techs are the strongest when your HP is at 1. We do not suggest trying to heal yourself, as she will just do the 1 HP move again. On occasion, she will attempt to steal some of your MP. Zeal has 12,000 HP. For defeating her, you get one MegaElixir.
40. Mammon Machine (Black Omen) Still weak from your battle with Zeal, your best bet is to use that MegaElixir you won. From here, pommel it with everything you have. NOTE: The Masamune absorbs energy from the Mammon machine, so you might want to have Frog in your party. When you attack it with Magic, it says that the machines attack power goes up. When you attack it physically, its defense goes up. So your best bet is magic attacks (the most powerful ones you have). When you attack it, and the Mammon M. stands still, it is weakening. Just kill it with your best techs or attacks: Luminaire, Flare and Shock/Dark Matter. The Mammon M. has 18,000 HP. For defeating it you get nothing.
41. Queen Zeal (Black Omen) This is the last battle between you and Zeal. There are three parts to this boss. A head, and two arms. Ignore the arms and go for the head. Make sure you use tech that only hits one section of Zeal, or you will get hit by a nasty counterattack from the hands. The arms' counterattacks are either taking that person's HP to 1, or MP to 0. She also has some nasty regular attacks that can hurt if you don't have good magical protection. Mega Bomb, Triple Kick, Uzzi Punch and Confuse work well here. The Lightning attack she does is not very powerful. Her Water attack is very powerful however. She has been known to use her Hallation/ HP to 1 attack, so beware of it: heal with Robo' Heal Beam. Queen Zeal has 20,000 HP so it's going to be a long battle no matter what. For defeating her, you get nothing. If you use Charm on her hands, you get a Prism Dress and a Prism Helm.
42. Lavos "Shell" (1999 AD) This is your first step into the final battle. You must now face the many forms of Lavos. Try to have Gold Studs as accessories and wear the best armors you have. These are the forms that Lavos takes:
1.Dragon Tank 2.Guardian and Bits 3.Heckran 4.Zombor 5.Masa & Mune (second form) 6.Nizbel 7.Magus 8.Black Tyrano & Azala 9.Giga Gaia 10.Lavos' true form
The last form has approximately 10,000 HP and is rather easy to beat, using Luminaire, Flare and Shock/Dark Matter. The other forms are just like their regular counterparts.
43. Lavos "Core 1" (1999 AD) Now that the outer shell is broken, it's time to attack the inner core. We advise a party consisting of Crono, Lucca and Robo with Gold Studs. Luminaire, Flare and Shock are about the best spells to use against the final forms of Lavos. Lavos has three parts to it. A central part, and two arms. In order to defeat the center, you need to defeat the arms first. Lavos will start with a powerful attack before you can get a move off. You may need to heal afterwards. The left arm appears to have less hit points than the right arm. The left arm has somewhere between 7000 HP and 8500 HP. The right arm appears to have between 8500 HP and 10,000 HP. Be careful about this, because when the left arm is gone, the right arm will cast a spell that will remove all of one characters protective magic, even that which is invoked by armor such as the Vigil Hat. When you beat the right arm, wait till Lavos casts a spell called Obstacle, which is a Chaos type spell. Then the main body's defense will decrease a lot. So now use Luminaire, Flare and Shock till it dies, healing with Robo when you need it. The central core may use Obstacle against you several times during the battle, or something called Flame Battle which is fairly powerful. The central body has about 20,000 HP. You get nothing for winning.
44. Lavos "Core 2" (1999 AD) This is it, the final showdown with Lavos. Lavos has three parts. A central body, a left bit, and a right bit. Be sure to have Crono, Lucca and Robo (in this order) with Gold Studs. The central body provides a protection for the right bit (the real core): so use Luminaire, Flare and Shock till the center dies. The bits will sometimes heal the central body, and the bits can also attack you. The central body will cast Time Warp which seems to enable itself to cast different spells depending on the time period you are in. After you've destroyed the central body, wait till the right bit shuts off his defense. Since there's no central body, the bits will counterattack each time you hit the left one. So you must only hit the right one: use Crono's Confuse and Lucca & Robo's DoublevBomb. Since Robo is next to the right bit (if you've made sure to put him in third place), DoublevBomb will do major damage to the right bit, doing more than 7600 damage at level 99! When you need it, cure the party with Robo's Heal Beam. If you don't have anymore MP, use a MegaElixir. The right bit will eventually revive the center body and the left bit if you killed them. The right bit will now raise its defense again. You need to repeat the process over again. The left bit has about 1500 HP, the center has about 10,000 HP, and the right bit has about 30,000 HP. Killing the right bit will kill the other parts of Lavos, thus beating the game!