Here's some other Pen Ward cartoons, the first was a part of the frederator cartoon podcast, the second was from Random Cartoons, which might be the first place Adventure Time was shown on tv because Nickeldeon was so stupid it passed it up, but hey Cartoon Network's Cartoon Institute (shorts from new animators) will come out one day right? Right? No, it won't. Which is strange because it has the pilot for Regular Show.
Bueno the bear is a early Pen Ward charcter. It's also usually Pen Ward's online account name for anything
Notice the voice of Tree Trunks anywhere?