Witches (Type of Creatures) are people that are known to practice magic. The Ghostbusters have dealt with their kind in almost every continuity.
According to Tobin's Spirit Guide, a witch named Kestrel is "An evil demoness who has no physical shape so she takes possession of people's bodies and makes them do terrible things." It is not known if this is the case for all witches or just Kestrel, in particular. However, it does appear that witches take on a minion either in the form of a familiar or lesser creatures like Goblins.
In modern times, witchcraft is still studied, usually in secret. A coven of Wicca from New York Community College fell under the sway of Cernunnos and he manipulated them into helping him cross over onto the physical plane. Cernunnos granted these witches the power of Level 5 Manifestation and turn their victims into hags.
Kestrel can possess people, transmogrify her hosts, gain their awareness, can imbue her hosts with increased strength, and commands a legion of Goblins.
Most witches have a mastery over magic and can cast spells. They utilize brooms as their personal transportation.
- In the episode "Lost and Foundry", the top row in Janine's crossword puzzle is filled in with the word "Witch."