Flambo

Flambo is a small fire creature that first appears in the episode "Business Time". It was shown when Finn was using his head to light a flamethrower. Because it is completely fire, it may be from the Fire Kingdom.

Finn uses the Flambo to light his flamethrower. He wears a special kind of glove when handling the Flambo, and squeezes its torso. This makes the Flambo's head get bigger. Finn then lets Flambo run away as he begins to melt icebergs, searching for junk to build a Gauntlet Dock.

Flambo returns in "The Chamber of Frozen Blades" acting as Finn and Jake's campfire while they are staking out the Ice Kingdom. Flambo apparently is their informant, having received a tip that Ice King was up to something suspicious. When Finn and Jake head off to investigate the castle, Finn tosses Flambo a piece of charcoal, which he eats.

He is also seen helping princess Bubblegum with a barbecue in the episode "The Real You" but causes a fire after Peppermint Butler stops watching the grill and argues with Chet.

Appearance
Flambo is completely made of fire and looks like a small animal, possibly a mouse or a cat. He has stubby arms and legs and a long, fiery tail. He runs on all fours but can also stand upright.

Trivia

 * According to Natasha Allegri, this creature's name is "falm-bo". Its name was later confirmed as "Flambo" in "The Chamber of Frozen Blades".
 * He has a Bronx accent.