Brain Beast

The Brain Beast or Snaked Armed Ruby Brain Beast makes its first appearance in "Tree Trunks."

It looks like a brain, with long snakes coming out of it for arms. There is a large ruby gem on its back and hitting this gem will kill the creature.

During the episode "Tree Trunks", the beast attacks Finn, Jake, and Tree Trunks in the Evil Dark Forest. Tree Trunks tries to seduce the Brain Beast with her "charm" and "elephant prowess". Finn saves Tree Trunks by hitting the magic gem weak spot and killing the ruby Brain Beast.

The Brain Beast later makes a cameo appearance in "Henchman".