Hambo

Hambo was Marceline's beloved teddy bear. She loved it ever since she was a kid. When Ash sold it to a witch to buy a new wand, she furiously dumped him.

Appearance
Despite being called a teddy bear, Hambo looks like nothing like one. Appearance-wise he looks like a dirty, torn up rag doll which had a missing eye prior to the first memory Finn and Jake enter.