General
Edits

There are some changes made throughout the dub of Pocket Monsters that
occur in just about every episode. So instead of mentioning these
changes in each and every comparison, I've gathered them all here in one
easy reference.
Show Title
The Japanese TV show, video games, and most other paraphernalia go
under the tile "Pocket Monsters." In America, the TV show, video
games, and other paraphernalia go under the title "Pokémon."
The "é" isn't really necessary, but it was included to aid Americans
with the pronunciation of the show's title creatures.
There are some people who believe that "pokemon" is a word made up by
the American dubbers. It isn't. It's used in the Japanese series,
game, etc. very frequently. In fact, here's what it looks
like:
You see, "pokemon" is shorthand for "Pocket Monsters." I wrote a
big explanation here,
so read through that if you haven't already.
Music
For the most part, the Japanese music is retained, but at the same
time it isn't. What does that mean? Well, most of the time
(and I say "most" because there are the rare examples) they keep the music
in the same place. That's fine and all, but the Japanese version
also has moments of silence in every episode. Well, the dubbers decided
they HAVE to have music playing throughout the entire episode to keep children's
interest, so they made their own music to fill in the "gaps." So
the dubbed version of Pocket Monsters has American music mixed in with
the Japanese original so that no silence is present. Actually, the
American music isn't terrible, and sometimes I have trouble telling
the Japanese music from the American music.
As for the opening themes, the American openings change as often as
the Japanese ones. What they do is take clips from the original Japanese
openings, snip a few of them out, add in some random episode clips, and
mix it all up to fit the new song that goes in the background. The
third opening, "Pokémon Johto," retains the most original Japanese
footage of the four openings.
Who's that Pokémon?
The little "Who's that Pokémon?" segment that airs right before
the commercial break begins and right after the break ends are what are
known as "eyecatches." They're called that because they alert the
viewer that the program has returned-they catch your eye. Outside
of Cartoon Network's Toonami, shows retaining their eyecatches were
practically non-existant. However, Pokemon does retain their
eyecatches, but the layout and music, as well as the presentation of them,
is different. Also, in the Japanese version, we don't hear the pokemon's
cries after their name is said...in the dub, we do.
Kids shout out "dare da?", which means "Who's that?"
in the Japanese version
Language
There's a common misconception out there that the original version
of Pocket Monsters has a lot of cursing, that Satoshi has a "dirty mouth."
This just isn't true. The subs released by Project Pikachu have Satoshi
saying things like "hell," "damn," and even "shit" on a regular basis.
But this just isn't true. If the characters ever swear, it's
done *VERY* rarely and only in extreme instances.
And even then, it would be something as light as "damn," and that's
only if Satoshi's reeeeeeeeeaaaally angry. So don't go around thinking
that Satoshi and the gang go around cursing like Eminem, because they don't.
PokéRap/Pikachu's Jukebox/Pokémon Karaokemon
It's just not there in the Japanese version. Episode ends, the
show cuts to a commercial break, and it returns with the ending credits.
There
is a Pokemon Rap in Japan, but it's a stand-alone song, not
a video shown after each episode. The dubbers write the song, find
the images of the pokemon, write the music, everything. As far as
the "Pikachu's Jukebox" "Pokémon Karaokemon" mess, that's all
American.
Ending Credits
For the first season of Pokémon (before it began on Kids' WB!)
and for whenever the show's aired on Cartoon Network, the show's ending
credits consisted of the credits running on one half of the screen, and
the video of the opening credits running on the other side as "Pokémon
Theme" plays in the background. When the show was picked up by Kids'
WB!, the credits remained on the right side of the screen, but the left
side contained (and still do to this day) commercials for other Kids' WB!
shows.
I think in England and Canada and Australia and the other countries
that air the English-dub, there are other ending animations. But
living in America, I wouldn't know.
The Japanese version has a seperate song and animation for its end-credits.
In fact, there have been over nine different themes. Also, as with
all anime, the Japanese credits list each voice actor as well as the character
he or she portrays. The American credits just list the actors without
telling who did which voice like most anime dubs.

Next Episode Preview
After the ending credits of each episode finish, Japanese viewers see
a preview of the next episode while "Mezase Pokemon MASUTAA" plays in the
background. The American version has no previews.
Preview for "Enju Gym! Ghosto Battle!"