Well, maybe not vargouilles vargouilles, but man-eating vampire bats have injured 40 and killed one person in Brazil. A tragedy to be sure, but also fodder for a great mystery-extermination adventure.
If I was a player who was presented with such a challenge, I don't know how I would handle it. But one thing's for sure: the reward would have to be really big to tangle with a colony of vampire bats!!!