The Mimic Monster is a character that lives in a dungeon in the episode "Dungeon." It is able to extend its body and form arms. When Finn sees that it is alive, he laughs and jumps away when it tries to punch him. Afterwards, it spontaneously vomits treasure from its mouth.
At first, it appears as a normal treasure chest, but when it opens, it reveals eyes and a mouth. The treasure it throws up consists mostly of gold coins with a few colorful gems sprinkled in.
- The Mimic Monster bears a strong resemblance to the Mimic, a Dungeons & Dragons
- The Mimic theme of a fake treasure chest that eats people is extremely common.