I have a list of all reported characters, but you will probably have to look up the names if you don't know what they look like:
All REPORTED Characters for Version 2
Toddler:
marutchi, kinakomotchi, hitodetchi, kuribotchi
Teen:
young mametchi, young mimitchi, oniontchi, hinotamatchi, ichigotchi,
ringotchi, nikatchi, hinatchi, propellertchi, ufotchi
Adult:
mametchi, mimitchi, marumimitchi, kuchipatchi, memtchi, pyonchitchi,
pochitchi, tarakotchi, kusatchi, gozarutchi, masktchi, zuchitchi,
kiwitchi, chohimetchi, debatchi, furuwatchi, dorotchi, urutchi,
nyorotchi, unknown sluggish thing, unknown reptile thing