Despite the fact that audiences rarely got to see his face, David Prowse played some of our favorite sympathetic villains. Sci-fi fans might recognize Prowse as the physical form of Darth Vader, while James Earl Jones provided the character’s voice.

However, Prowse also made a name for himself in the horror genre, frequently acting as Frankenstein’s monster in films like The Horror of Frankenstein (1970) and Frankenstein and the Monster from Hell (1974).

Though the monster made a fearsome foe, behind the scenes, Prowse was more than suffering for his art. The character required a heavy hand of special effects makeup, as well as a rather large and bulky costume to match.

“I could only wear the costume for short periods,” Prowse told the ABC Film Review, according to Hammer Films: An Exhaustive Filmography, by Tom Johnson and Deborah Del Vecchio. “The costume got terribly hot after a time working under all those studio lights, and, for part of the day, I couldn’t see where I was going as the mask covered my eyes.”

Hammer films were known for their more gruesome nature, and so the more frightening elements of the film were often intensified.

Terence Fisher, who directed Frankenstein and the Monster from Hell, sided with Prowse.

“I disagreed from the start and tried my best to limit the makeup,” said the director. “However, they had sold Paramount on the idea that the monster would be this grotesque hairy beast, so I could not make him human, but I reduced him as far as I could without ruining what they had sold it on.”

Fisher’s efforts were well appreciated by Prowse, who was able to provide an incredible performance despite these limitations.