Boomerang bottle

The Boomerang Bottle is a green bottle that Finn threw in the episode, "The Duke". It acts like a boomerang, and when Princess Bubblegum was hit by it, she turned green, lost most of her hair, and became more antagonistic. This may be an "ugly potion" of sorts.

Appearance
A green, boomerang-shaped bottle with a screw cap. Because of its shape, it functions as a boomerang.

Significance
Finn and Jake were seen throwing bottles from a wheelbarrow at a wall. Finn then finds the Boomerang Bottle. He states that it looks stupid and then becomes interested as he wanted to see how it would fly. He then threw it, but being the shape of a boomerang, it turned direction and broke a window in Princess Bubblegum's Castle. Princess Bubblegum was in the room, and her skin color turned green and she lost a lot of hair. Unfortunately, she thought that the Duke of Nuts threw the potion. She then commands Finn and Jake to arrest the duke.