By far the worst of the Morlocks (and the only one to be shot in black & white) was “The Ghost of Professor Morlock.” Top-billed Amy Ball would only agree to shoot for a single day and appears in less than seven minutes of the film and Jesse Merlin (who was in a bitter money dispute with the producers) was seen as Morlock for a little more than ten, with his performance edited together from outtakes and unused scenes from the previous movies.
The rest of the film is Amanda Globe’s fiancé Brick Stockman (a character who never appeared before and mercifully never showed up again) appearing at the séance parlor of gypsy mind reader Olga from the last entry “The Testament of Professor Morlack” (played again by Jaz Davison, whose performance was the only redeeming aspect of the film) to determine what became of the missing Amanda. They spend 65 minutes sitting in front of a dark gray curtain reciting inane dialogue to each other with only occasional cutaways to Tom Ackerman (who was rumored to be high as a kite on reefer throughout the shoot) as Ruprecht chasing an Amy Ball look-alike through cardboard sets.
Brick Stockman was played by Glenn Simon, an actor best known for his performance as G-Man Chuck Chuckman on the TV series “Red Hunters,” in a laughably wooden performance. Simon’s mysterious murder less than a year later is still a subject of Hollywood gossip, when it came out that he was a well-known transvestite and that his death was a hit arranged by the head of a studio who'd dress up with him in sequin gowns and troll the streets of Los Angeles on Saturday Nights. The scandal was well-chronicled in the book "Drag Queen: The Mysterious Death of Glenn Simon."
When Merlin refused to appear in this film, the producers used outtakes and unused footage from previous "Morlocks" and weren't particular about its quality. Included in the final print is this outtake from "The Return of Professor Morlock" where Merlin and Amy Ball laughed after a cameraman broke wind during filming.
“The Ghost of Professor Morlock” is frequently named at the top of lists of the worst films ever made and was memorably lambasted on an episode of “Mystery Science Theater.”