'Therian' is basically the catch-all term for were-anythings, as far as I'm concerned. Mr. Barret here is a coyote therian - close, but not quite a werewolf/lycanthrope.

Shifting isn't always painful for therians, but a sudden change(triggered by god knows what) can catch them off guard. He managed to wriggle out of his shirt, shoes, and one sock before what was left got ruined by the shift... The tear over his knee is from his hand growing the claws when he tried to ditch the pants.

Meh, he's had worse random shifts... I'm sure.