Steven

A goldfish belonging to Magnus Burnsides. His full name is Lord Steven Q. Fletcher Esquire the Goldfish III (maybe).

Steven lives in a magical snowglobe-sized glass ball, which was inside the Mystery Bag Magnus bought at Fantasy Costco in Episode 17: Lunar Interlude I: Carnival Chaos.

Steven has his own null suit that he wears in Lucas's crystalizing laboratory during Chapter 4: The Crystal Kingdom.