Belleranthon is a large and powerful ghost that resembled a giant purple cloud mass with multiple yellow eyes and red irises.
It is explained that when Mrs. Faversham was a little girl, her father wanted to make her life better, even though she was pretty much happy with the way her life was. In order to do this, Mr. Faversham summoned Belleranthon only to find out that he was too powerful. The best he could do to fix his mistake was to imprison the creature within the attic. It was consumed with hatred for Faversham and obsessed over exacting revenge. Unaware of the time that passed, it enlarged its domain and assumed absolute control of the attic.
70 years later, Mrs. Faversham could no longer stand Belleranthon's tormenting noises and called the Ghostbusters to get rid of Belleranthon. On the first encounter, the Ghostbusters temporarily broke its concentration, by shooting at two objects at once, and retreated from the attic. After hearing Mrs. Faversham's story, they concluded they had to lure Belleranthon into the open and reveal its true form in order to trap it. Belleranthon was trapped after Slimer impersonated Faversham's father to bait the creature, as he wanted to have revenge against Mr. Faversham. Egon Spengler lured it to the trap door and trapped it.
Belleranthon can control objects and make them function as bodies for him. While he was in control of everything including there being a door, it is suggested that he could not leave the attic.
Even when in a host body, Belleranthon could project balls of psychokinetic energy.
In his true form, Belleranthon could generate a tornado and lightning within only the attic.
- In What in Samhain Just Happened?!, on page nine, a coat rack similar to the one used by Belleranthon is seen near a table.
- On page 10 of Ghostbusters Crossing Over Issue #3, the Doom Ghost's fog form is visually based on Belleranthon.
- Marsha Goodman (1986). Episode Call Sheet and SAG Report - "The Thing in Mrs. Faversham's Attic" (1986).
- Egon Spengler (2009).The Real Ghostbusters- "The Thing in Mrs. Faversham's Attic" (1987) (DVD ts. 14:12-14:16). Time Life Entertainment. Egon says: "I think that Charles Faversham tried to make a good life for his daughter."
- Agatha Faversham (2009).The Real Ghostbusters- "The Thing in Mrs. Faversham's Attic" (1987) (DVD ts. 12:39-13:03). Time Life Entertainment. Agatha says: "One night, he went up into the attic. There was a terrible storm that night. Silly of me but I actually imagined it came from upstairs then I heard something quite frightening."
- Egon Spengler (2009).The Real Ghostbusters- "The Thing in Mrs. Faversham's Attic" (1987) (DVD ts. 9:34-9:37). Time Life Entertainment. Egon says: "That thing has absolute control over everything in the attic."
- Egon Spengler (2009).The Real Ghostbusters- "The Thing in Mrs. Faversham's Attic" (1987) (DVD ts. 05:06-05:07). Time Life Entertainment. Egon says: "Right off the scale."