John DiMaggio refused to work on any shows from Cartoon Network.
Jake the Dog is , along with Finn the Human , a fictional character and one of the main cast in the American animated television series Adventure Time created by Pendleton Ward .. Adventure Time. Adventure Time. Pendleton Ward. Pendleton Ward. Dog. Dog. Finn. Finn the Human. Finn the Human. Finn the Human. animated television series. List of animated television series. He is voiced by John DiMaggio .. John DiMaggio. John DiMaggio. The character made his debut in the original pilot .. the original pilot. Pilot ( Adventure Time ). Jake is Finn 's best friend and adoptive brother .. Finn. Finn the Human. He is a shape-shifting dog who is in his 30s in `` magical dog years '' .. He was conceived by Joshua and an extra-dimensional creature and as a result , 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 confidant and 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 .. Finn. Finn the Human. Jake is in a relationship with Lady Rainicorn voiced by Niki Yang ; they have five children together as seen in `` Jake the Dad '' .. He met Lady in the pilot episode and is quite skilled at playing the viola , which houses a worm called Shelby .. viola. viola. The character has received largely positive critical reception .