Karen Singer

She is Bobby Singer's late wife, and the reason why Bobby goes into hunting.

Background
Not much is known about her other than the fact that she was married to Bobby Singer and one day got possessed by a demon. With the demon inside her, it caused her to be rabid and Bobby was forced to kill her. Her death pushes Bobby into the hunter lifestyle.

She appears in Bobby's nightmare, very angry at Bobby for killing her. She chases Bobby all over the house in the state she was probably in when she died.