|Introduced in||"Freak City"|
A rat appears inside the broken TV set in the very beginning of the opening sequence.
When Jake lies down in a pile of trash, a number of rats ran up to him and started crawling all over him, which Jake didn't seem to mind at all.
City of ThievesEdit
There was a rat in the episode, "City of Thieves" who had its cheese stolen.
Memory of a MemoryEdit
From Bad to WorseEdit
Science is Princess Bubblegum's lab rat. It is trained to read her notes and gather ingredients for chemical formulas. Princess Bubblegum awards Science the Royal Medal for Heroic Bravery for creating the formula that reverses the Candy People's zombification.
Holly Jolly Secrets Part IEdit
A giant rat is seen in "Mystery Dungeon," where it bursts through the floor of the destroyed kitchen after getting a scent of Tree Trunks's pie. It was then knocked out unconscious by Lemongrab, angry at the fact the rat ate the pie.
A family of mice were seen to live in the walls of the Tree Fort in "Shh!"
Squirrel is a squirrel who hates Jake for not printing his letters in Jake's newspaper column. Squirrel attempts to get another letter to Jake by throwing it at his feet, but Jake walks away without noticing. Squirrel attacks Jake at the end of the episode.
Squirrels appear in "Storytelling." They are sleeping in a hollow tree when Finn peeks in the hole to see if they are kissing. Finn's presence startles them so they run in a circle and bump heads, knocking each other out.
Rabbits appear in Princess Potluck, where the Ice King attempts to use them to sabotage Princess Bubblegum's potluck, however, he never used them.
- Rats generally have grey or dark navy blue bodies with grey tails.
- Mice have a similar appearance to rats, except that their ears are larger and they do not have protruding front-teeth.
- Squirrels are brown to red-brown and have bushy tails, curled at the end.