The Winged Demon was one of the demons that guarded the borders of Purgatory.
The Winged Demon was one of many demons that guarded the borders of Purgatory. In particular, it presided over The Pipeline. While Al Capone and Meyer Lansky ushered several souls to the real world, the demon demanded a soul to eat. Jiff was the soul to be given as part of the deal between The Bosses and the demons. Peter Venkman saved Jiff by throwing an old woman at it and then tore the demon to pieces. Everyone else was showered in the demon's innards.
The Winged Demon has a conglomerate of features from several animals- the head and body of a lion, wings of a bat, the eyes of a fly, and hooves for legs.