Gray Fly is one of the mercenaries hired by Dio Brando during the third arc of JoJo's Bizarre Adventure,and he crossed in the MEH.
Gray Fly is a assassin who is specialist not only in blowing buildings, ships and planes but also to make everything look like an accident, leaving no evidence of his crimes. Hired by Dio Brando to kill Jotaro Kujo and his group, he attacks them on a plane between Japan and Hong Kong. They see a big stag beetle flying inside the plane, who attacks them and the passengers. They are unable to attack it, as it moves very fast. An old man wakes up, but Kakyoin knocks him out, deciding to fight the beetle by himself. He traps the beetle around the strings of his stand, tearing it apart. They then discover that the old man was Gray Fly, who was controlling the beetle, as he starts bleeding from his tongue and dies. They are forced to land the plane in the sea, since Gray Fly had already killed the pilots.
Gray Fly's stand, Tower of Gray, takes the form of a giant stag beetle. The thing is very fast and agile, and can tear through flesh easily.