Goop

Goop is a Boggle, a chaotic evil little fey goblinoid that lives under Bailey Fanteaser's house and messes with him constantly. It loves shiny "treasures" and chaotic pranks. It can excrete sticky or slippery goo through its skin and travel through small dimensional rifts to teleport.

Goop used to be in the service of the Sea Hag, and she has offered boons in exchange for his unwilling return.