Gorilla Town
There is a zookeeper watching over your enclosure at Night. If you are targeted by any Night action that would be detected by a Watcher, the action fails and the zookeeper fatally shoots you. This cannot be blocked by the action itself, but if you somehow managed to obtain a Bulletproof vest beforehand, then you won't die. Death-by-zookeeper is treated as a suicide, rather than as a kill by the player who attempted to target you.
While a hypothetical Bulletproof Gorilla could be shot multiple times in one Night (and would possibly be an overpowered role), only one player can be the cause of a single zookeeper bullet. If you were targeted by multiple actions, only the first one that could have triggered your ability, according to the mod's action resolution scheme, does so. (In the case of a tie that can't be decided logically, it should be whichever was submitted first; if this isn't enough to decide, the mod should roll a die.) The rest fail too, though.
Upon activation of this mechanic, the other player—but not their alignment, their role or the action they used—is publicly identified by the mod the next Day. It should be unambiguous that they're being identified for visiting the Gorilla, and that the Gorilla is you, even if you somehow survived.
Inspired by certain events that took place four years ago today.
