I'm not a squarepegger, but damn if this didn't make me think of an episode of Mighty Max, where a scientist engineers werewolves, only for a -real- (supernatural?) werewolf to show up and not be very amused by it. A Ctually it might have used his blood as a template, I forget.

Square Peg Round Trope / Definition Drift

We need to do a bit ofthinking regarding the definition of this trope, and possibly its name. This Shape Shifting trope isn't simply about characters who can assume a monstrous form — that's part and parcel of Voluntary Shapeshifting — this trope is specifically when a character's shapeshifting abilities cause them to be mistaken for the actual monster by other characters.