Peter Venkman rescued Egon from the creature after the Scaredy-Cat Ghost told him the location of Egon's soul in exchange for being put in the Containment Unit instead of being imprisoned in the sinister atmosphere of the Netherworld.
The monster wasn't too happy about Peter taking his "trampoline" away, so he followed him out of the portal. The ghost made it difficult for the Ghostbusters to banish the demon that possessed Egon, but Slimer was able to tickle the entity's foot, enabling the Ghostbusters to send both creatures back into the Netherworld.
- On the visual commentary of The Real Ghostbusters Complete Collection, writer Marc Scott Zicree confirms this entity was inspired by the Merrie Melodies short "Duck Amuck." 
- ↑ Marc Scott Zicree (2009).The Real Ghostbusters- "Egon on the Rampage" (Visual Commentary) (1987) (DVD ts. 18:26-18:29). Time Life Entertainment.