El Diablo

The guy's name is Miguel Vargas, but he calls himself "El Diablo", and is from Denver. He went crazy one night and killed six people in two different homes. They call him the "Vampire Killer" because he bit his victims on the neck during or after killing them. Last anyone heard, he went east. Bob the Bounty Hunter in Hoover Dam has a bounty out on Diablo's head; dead. When he dies, he drops a severed head item. Bob knows a guy who was going to look for Diablo out in Dogtown, but he never came back... El Diablo got him.

El Diablo is insane. He really thinks he's a vampire. He refuses to come out during the day (he's only on the map at night) and says he started killing that night in Hoover Dam because "some bitch stole his hat".