Jake's Dream Sequence when he falls asleep during Princess Bubblegum's lecture:
Jake: Where am I?
(the camera pans over to show a tiny giraffe, a tiny snowman and a tiny version of Tree Trunks)
Tiny Snowman: Jake, you're president now!
Jake: Oh my gosh!
(Jake proceeds to sway back and forth while the tiny snowman, giraffe and Tree Trunks all clap.)