Thats bob odenkirk dressed as a vampire!!!
No dialogue though
shareThere's this deleted scene where he sings, it's terrible quality but here you go;
https://www.youtube.com/watch?v=a9UirwIAhUM
Bob Odenkirk is good friends with David Cross, who has a scene in this movie (he's the UFO enthusiast). David probably got him a cameo.