Anime: Digimon Adventures, Digimon Adventures
2 (Season 2), Digimon the Movie (the first three OVAs stuck together), and possibly
OVA 4
Manga: I'd assume she's in the Digimon Adventures manga (not that I've read it)
Gatomon is by far the greatest character ever
created. She's cute, and severely underused. She's also one of the only characters
to be involved in a decent major storyline (Ken and Hikari/Kari being the others).
Accidentally separated from the other Digidestined's digimon before birth, she
became Myotismon's most loyal follower. In Myotismon's search on Earth for the
eighth Digidestined child, she starts questioning her loyalties and learns that
she's actually Hikari's, the eighth child, digimon. Then after betraying Myotismon
and joining the other Digidestined, she becomes just another character with
relatively little to do (since most attention is devoted to Taichi and Yamato
and their digimon). However, the shocking underuse of her does not lessen her
absolute greatness and superiority over you.
Tailmon is actually her original name, but I
had to make an exception and use the dub name Gatomon due to a long-running
in-joke between Waller and various other people (it will not be explained here,
but /whois Gatomon and you should work it out). As a result of this in-joke,
all opinions in this description should be taken as 100% fact.
Note: Waller wrote this description.