Daxflame is some kid who runs a popular video diary on youtube. There is debate surrounding the legitimacy of the videos, and if you watch a couple you'll understand why. I'm pretty sure the kid is just a really good actor... I've heard he's an improv student or something. Regardless, he's an absolute riot. If you don't think he is funny, you are wrong.
I would strongly recommend checking out a number of his videos (if not all of them). Some of my favorites include "I Pulled the Ultimate Prank at Lunch", "Trouble in PE Again" and (its a little long) "The Convenient Truth."
Be sure to click "more info" on the descriptions because they're pretty good, as are the tags he puts on each video.