Jake is Finn's best friend and adoptive brother. He is a shape-shifting dog who is in his 30s in "magical dog years". He was conceived by Joshua and Margaret. As a puppy Jake rolled around in a puddle of magic mud, giving him magical abilities. Jake can stretch, shrink, or mold any part of his body to any shape and almost any size, ranging from becoming gigantic to becoming incredibly small. He acts as a confident mentor to his energetic brother, though has a tendency to give somewhat questionable advice. Jake has a laid-back attitude in most situations, but loves adventure and will eagerly fight when he needs to. His powers help Finn considerably in combat and transportation, but are also sometimes used as nothing more than jovial forms of expression.