Police don't know, but they're looking for whoever donned a flowing costume and put a bizarre and alarming parcel on a Long Island doorstep Friday.
The package included an object that looked like a grenade, plus a white powder, a book and some candy. It wasn't addressed to anyone at the address on West Broadway in Woodmere.
Authorities ultimately determined that the grenade was a toy, and the powder was sugar. No one was hurt.
Still, police say whoever is responsible could face a charge of placing a false bomb.