The ghost of a 17th century witch and her stooge Gronk return for revenge on the descendant of the Edward Spencer who broke her spell at the Salem Witch Trials.
The Phantom of Vaudeville, a masked ventriloquist with his dummy Elmo, seek revenge after suspecting Spencer, Tracy and Kong of being the song and dance act that upstaged them decades earlier.
The Ghost Busters become embroiled with Egyptian Queen Forah and her Mummy as they search for the ape-sorcerer Simios, who in turn can bring them to Spen-Zah, possessor of the secret of immortality.
Spencer stumbles onto the scene when Dr. Centigrade is searching for a warm-blooded heart to transplant into the Abominable Snowman. Final episode of the series.
Hoping to remove the curse of the werewolf from hapless Harry Albert, Gypsy fortuneteller Sophia comes seeking to steal the Baldus Lupus Amulet that Spencer recently unearthed.
Merlin and jester Gronk are pursued from the Great Beyond by their nemesis Morgan Le Fay, who intends to trap them in this era. The Ghost Busters befriend and assist the broken-down magician in his battle with the beautiful sorceress.
Dr. Jekyll and Mr. Hyde are living as two separate persons, with the Neanderthal Hyde driving insane the urbane Jekyll. Only by drinking a potion made from a person without any personality can Jekyll ever hope to be set free from Hyde.
The ghosts of Erik the Red and Brunhilda return to plant a Viking banner and establish their claim to having discovered America prior to the loathsome Lothar the Hun.
Those ghostriders in the sky are the spirits of Billy the Kid and Belle Starr back to round up a new gang of cattle rustlers. The Ghost Busters disguise themselves as cowboys to get the Dematerializer drop on 'em.