Kenneth Williams is performing admirably as the villainous "Dr. Watt." His scheme isn’t about transforming shop displays into attractive women; instead, he aims for the opposite effect. Tom Clegg portrays his dangerous assistant, “Oddbod,” who obtains what's needed for Dr. Watt's plans, while Harry H. Corbett embodies "Insp. Bung," the detective tasked by Scotland Yard with apprehending this criminal. This installment is notably among the stronger entries in the franchise. It functions as a satire of horror films, particularly those from Hammer Films, and contains considerably less overt suggestive humor and double meanings than many other “Carry On” movies. Corbett conveys much of his performance through subtle expressions and glances, and both Williams and Fenella Fielding provide excellent performances alongside a dependable supporting cast who all contribute to the consistently entertaining narrative that moves along briskly for ninety minutes. The special effects appear rudimentary, resembling items found in a grocery store’s spice aisle, possibly with some porridge or textured coating added for effect, and Eric Rogers composed an upbeat yet unsettling score to guide viewers through the fabricated suspenseful moments. It doesn't elicit uproarious laughter, but it effectively mocks the genre and has aged reasonably well. Just don't anticipate being frightened in any way.

Source on TMDB