Ape

Token Upgrade
If upgraded with a Pet Token, Ape will use his first action in dungeons to transform into super Ape. The transformation will last for class level / 5 actions, and gives a class level% boost to all stats and Ape will hit twice. This means at class level 100, Ape would have a 100% boost to all stats for 20 actions. This only works once per room/floor.

This is not very useful until around CL 50+ and works if evolved into any class except Mage.

Recommendation
Ape can be Unlocked during a UPC while pets run item camps and level up, since the challenge requires no rebirths for a long time. Ape can be evolved into Adventurer to capitalize on its growth campaign bonus, and then Class Changed to a dungeon class later to utilize its token upgrade once you have stronger growth campaign pets.