Jake is a magical dog in Adventure Time with Finn and Jake. Finn refers to him as his friend and gets offended when others say it's his dog. He is a magical dog that can connect his mind to the internet by meditating. It is also known that he can change in size and has extensible legs, which came in handy for saving Princess Bubblegum. Jake seems to be interested in the princess's Rainicorn. He also plays the viola.
Appearence
Jake is light-brown dog, with large eyes that characterize him greatly. His appearence can change many times since he has the ability to morph. When going to the Ice Kingdom, he wears purple booties.
Jake as a Lumpy
Personality
Jake is mainly laid-back. He often cracks jokes at serious times, and supports Finn. As a matter of fact, Jake is never really shown being serious at all. He always has great advice when something bad happens, like in the episode Evicted!, where he suggests house-hunting. Jake is in love with Princess Bubblegum's Rainicorn, a mixture of a rainbow and unicorn. This is shown a lot in My Two Favorite People. He seems to be afraid of Marceline because of all the scary stories he hears from "reliable sources".
Jake playing the viola.
Quotes
"Yeah I know what Ice King means! A big nerd!"
"Wait dude, I'm connecting to the internet with my mind"
"Please don't suck our blood!"
"Vampires will kill you man!"
"House hunting is wild!"
"Sleds are for suckers! Just ride on my gut!
"Jiggler! What the heck?!"
"Sleep?!What?! We were supposed to play the viola together!"
"I'd rather be dancin' with babes!"