The starfish in the dentist’s fish tank is named Peach.
Peach is one of the members of the Tank Gang, the group of aquarium animals living in Philip Sherman’s office tank. She is a pinkish sea star and often acts as an observer, watching events in the dentist’s office from the glass.
Peach is sometimes confused with Deb, Bloat, or Jacques because they are all part of the same Tank Gang. Deb is a damselfish, Bloat is a porcupinefish, and Jacques is a cleaner shrimp. Peach is also voiced by Allison Janney in the original English-language film.
The tank’s inhabitants are central to Nemo’s escape plan. After Nemo is captured and placed in the aquarium, the group helps him resist the dentist’s plans and eventually escape into the harbor. Nigel, the pelican, is their outside connection to the wider ocean world.