2000 years later, the disciple found a mortal who could open the portal that imprisoned his master. The mortal was named Dr. Crowley who was obsessed with his hatred of lots of stuff, including Halloween. The disciple took a human form, went by the name of Fairweather, and became employed as Crowley's assistant. Together, they worked to get rid of Halloween once and for all and constructed the Electronic Positronic Anti-Halloween Machine. The device was almost complete and only required a P.K.E. Meter to focus it. 
The Ghostbusters refused to help Crowley get rid of Halloween, but while they were distracted, Fairweather stole a P.K.E. Meter. Crowley played right into Fairweather's plan and activated the machine. By erasing all traces of Halloween, the machine breached the Halloween Deal which resulted in the opening of the Halloween Door for Boogaloo and his demons. Fairweather then gloated and revealed his true form to Crowley. He wasn't seen again after his humanoid disguise was removed, but it was possible that when Boogaloo and his forces returned to the Netherworld, he was taken with them.
Fairweather resembles a composite creature similar to the Sphinx. Fairweather has the head of a dog, what appears to be a body of an armadillo, insectoid legs, and one arm is a tentacle.
Fairweather is a liar and a thief. But he is obedient to his master, Boogaloo, and enjoys what he does.
- In the visual commentary on the The Real Ghostbusters Complete Collection, writer J. Michael Straczynski compares Dr. Crowley and Fairweather to famed actors Boris Karloff and Peter Lorre. 
- On the last page and last panel of What in Samhain Just Happened?!, Fairweather, in his true form, makes a non-canon cameo in the left side of the panel.
- On page seven of Ghostbusters Issue #5, Fairweather, in human form, makes a non-canon cameo on Manhattan alongside Dr. Crowley.
- ↑ Dr. Crowley (2009). The Real Ghostbusters - "The Halloween Door" (1989) (DVD ts. 08:14-08:16). Time Life Entertainment. Dr. Crowley says: "Tell me it's ready, Fairweather."
- ↑ Fairweather (2009). The Real Ghostbusters - "The Halloween Door" (1989) (DVD ts. 12:02-12:05). Time Life Entertainment. Fairweather says: "My boss. And yours."
- ↑ Dr. Crowley (2009). The Real Ghostbusters - "The Halloween Door" (1989) (DVD ts. 04:58-05:01). Time Life Entertainment. Dr. Crowley says: "We needed their P.K.E. Meter to help focus the machine."
- ↑ J. Michael Straczynski (2009).The Real Ghostbusters- "The Halloween Door" (1989) Visual Commentary (DVD ts. 04:43-04:52). Time Life Entertainment.