The flame cloak is, as the name suggests, a cloak made out of flames. Finn is seen wearing it in "Dungeon Train" after he somehow obtains it from a boss fight as loot. He wears it throughout the rest of the episode as he takes Jake's pack and retrieves his future crystal.
- It is unknown if it actually burns the person wearing it. It could be Finn's resistance to fire gained from being with Flame Princess that keeps him ignoring it or it could be conditioned with a piece of fabric or metal on the inside.