Finn reminds me a whole bunch of Maxwell, the main character of Scribblenauts The Game of Creating (and Destroying bwuahaha) things to solve puzzles. Like, Maxwell has a little hat thing, but it's red and he has a dot-dot-curve face like Finn, too. His world is basically a fantasy land (seeing as how anything he writes in his handy dandy notebook comes to life). He doesn't have a partner in crime, but if you type Maxwell into his notebook, an evil version of him pops up and starts making weird things like a metaphysical neurotic grenade launcher (technically just a fidgety gun that shapeshifts when it dies). The game is fun and I like harrassing the people I conjure.

But yeah, the whole concept of the game and Maxwell remind me of Adventure Time and Finn.