When Cell first got out of his 2nd Larva state, he found out that his time had hardly anyone to absorb. So he stole Trunks's Time Machine and went to the date that he entered in on the data. To do this, he had to go down to his Egg Form and evolve all over again. This was something he was willing to do.
Larva Stage 1 Absorbed: No One.
Cell was genetically created with cells from Goku, Vegeta, Frieza, Tien and some other great fighters. Cell started out as a small little speck in a tank.
Larva Stage 2 Absorbed: No One.
When Cell grew to normal size, he became a (More than usual.) bug like thing, that walked on 6 legs. After a couple of days in this form, he grows out of the shell, becoming Imperfect Cell.
Imperfect Cell Absorbed: Countless People.
Cell is a great design, created by Dr. Gero. He has the cells of Goku, Frieza, Piccolo, Vegeta, Tien, Yamcha, Gohan and the other strongest fighters. Cell was programmed to absorb Androids #17 and #18 to reach his perfect state. In this form, he absorbs countless numbers of people to become stronger.
Cell Form 2
Semi-perfect cell Absorbed: Android #17.
Cell's next state that he goes into after absorbing Android #17. This form of Cell took down Android #16 in a blink of an eye. Tien was able to hold him back, but had an really hard time doing so, until Vegeta and Trunks came in. Vegeta started wailing on him like there was no tomorrow and out smarted him in every way. Until Cell out smarted him into letting him absorb Android #18 and becoming perfect.
Perfect Cell Absorbed: Android #18.
Cell's best and most perfect form. He has no equal in the universe. He can regenerate all his limbs and Kienzans do not effect him at all. He knows all the moves that the Z Fighters know. (Except for a select few.) Cell proves to be way to strong for any of the Z Fighters, until Gohan gets insanely mad at him killing Android #16 and turns to the Super Saiyajin 2 state. In which case Cell has no power over.
Giant Perfect Cell Absorbed: Androids #17 & #18. (Still.)
In Cell's frustration with how to defeat Super Saiyajin 2 Gohan, he grows into a large fighter with huge muscles, putting all of his strength down on the board and getting rid of a lot of speed. Gohan takes him down easily, kicking him in the chest and making Cell puke up Android #18, turning him back into Cell Form 2.
Self Destruct Cell Absorbed: Android #17.
Cell finally finds a way out of this. Since he was in his second form once more, he decides to destroy himself and Planet Earth. He grows to an enourmous size and explodes at a time that he can not control. Goku uses Instantaneous Movement (Shunkan Idou.) to bring him to King Kai's Planet (The only place he could think of.) to let him self destruct there, instead of on Earth. He indeed blew up the planet and half of Snake Way, but he was not done yet...
Ultra Perfect Cell Absorbed: No One.
This is Cell's form after self destructing and destroying King Kai's Planet. He regenerated out of one brain cell, that was the entire cell of Piccolo's regeneration. He used the Instantaneous Movement to get back to Earth as his new powered form from death. He had lost Android #18, but his body copied her data, allowing him to stay perfect. Gohan was no match for the new Cell, but killed him after firing the biggest and strongest Kamehameha ever.