Probably that time Charon when tore his face off, as I noted a few months back in "Superhumans I Have Known (and, on occasion, been)":
Honorable mention goes to "Evil Universe Force" from the same article.
CharonOh, man, Charon. This was in a campaign I was actually playing instead of running, so I got to see this stuff from that side of the screen. Charon claimed to be the figure from Greek myth. Claimed. Thing was, he was basically a happy-go-lucky, vaguely Mediterranean brick. Nothing about him said “Boatman of the Dead.” He talked like one of the “Wild and Crazy Guys” from that old SNL sketch. He was, frankly, kind of a joke.Then, about six or seven sessions into the campaign, he got captured by Arnim Zola (yeah, really). He was very well-secured, his strength completely nullified. At that point, his player looked at the GM and said, “It’s time to drop the mask.” He then proceeded to describe, in horrible detail, exactly how the flesh melted away from Charon’s body, revealing a bloody skeletal visage. The skeletal form was a horrifying engine of destruction, and it broke Zola’s captivity with ease (also the dude’s mind). It was exactly the sort of unforgettable moment that makes me love gaming so much.