I was recalling to my brother a bizarre animated movie I saw once. I used to remember more, but here goes with the details almost 15 years later.
If it helps to frame when/where it aired, my summers as a kid ran from Memorial Day Weekend through the first week of August. This had to be the summer of 2004. Beavis & Butthead Do America was reairing on premium movie channels like HBO and Showtime A LOT, and since reruns of the show were marathoning regularly on MTV2, I would watch any time it was on.
I either fell asleep or went into the office to use the computer during an afternoon/early airing of B&B Do America. I was the only one home, so what I saw in what came on after struck me a little harder than normal (I was 9).
It was an animated movie, the animation a bit scratchy, not quite Dr. Katz like, but with moving shading and whatnot. Dark, yet deep colors. Skies and backgrounds gave me a Rocket Power vibe. The only thing I vividly remember is a guy sitting on the sidewalk at an intersection. I can't remember for certain, but I think he then took his shirt off. (I at least remember that being part of what I told my Mom I had seen.) I believe it was a blue shirt. What I do remember next was the guy just sets himself on fire. People casually stroll by as he burns, the shot slowly pans out, and then it fades to black, into the next scene.
Not exactly scared, but utterly confused and disinterested, I remember switching to my PS2 to play racing games and not finishing the movie.
I can’t name what it was, but I definitely saw something closely matching this description once. I don’t remember the man taking his shirt off, but I do remember the shaky colours, and that the man was drawn in a highly realistic way, so the film may have been rotoscoped.