He was portrayed by the late Rick Aviles.
When Willy is introduced, he attempts to rob a wallet belonging to Sam Wheat (the protagonist of the film). This results in a fight, and Sam is killed. Later on, we see that Willy has Sam's wallet. Although he fails in getting the codes. He then tries to break into Molly's apartment to find the codes, but Sam (now a ghost) has a cat to scare Willy into fleeing away from the apartment. Sam later finds out that his friend Carl was the one who sent out Willy to steal Sam's codes to launder money from bank accounts, thus Carl is partially responsible for Sam's death.
Upon hearing that a medium named Oda Mae has withdrawn $4 million from the bank (under Sam's directions), Carl and Willy head over to her apartment to attack her. Fortunately, Sam physically attacks Willy, who then attempts to escape but is killed in a traffic accident. Willy's ghost arises from his dead body and Sam taunts him by saying, "You're dead, Willy!" A group of howling shadows then appear out of the nowhere and pulled a screaming Willy into the darkness, presumably to Hell for his sins. Carl would later join Willy in Hell after being stabbed to death in the abdomen by sprinting glass from a falling window.