Peter has a PhD in psychology and parapsychology and is known for his dry humor, which he uses to try and impress women, especially Dana Barrett. Although he doesn't take his work as seriously as Ray and Egon do, he is considered the leader of the GhostbustersTM.
The concert cellist is the GhostbustersTM ' first client. She lives in the same apartment building as Louis Tully. She finds Peter Venkman rather incompetent, as he'd rather flirt with her than take care of their traps. She is possessed by a spirit that later turns her into the Terror Dog Zuul.
Both of these horned dog-like demons, Zuul The Gatekeeper and Vinz Clortho The Key Master, are faithful minions of the evil god Gozer. When he wants to destroy the world, the Terror Dogs possess Dana Barrett and Louis Tully, using them to open the gate to Gozer's world. But, the GhostbustersTM are already on their way to stop this from happening!