Fairweather

Fairweather was the assistant to mad scientist Dr. Crowley, and helped him build his machine to banish Halloween forever. He was actually a demon in disguise, doing the bidding of his master, Boogaloo. After the Halloween Door was opened Fairweather shed his human disguise. What became of him after this is unknown although presumably he was sent back with Boogaloo and the others after the Ghostbusters managed to renew the Halloween Promise.