Nastassja Kinski was having trouble coming up with tears for a scene in To the Devil... A Daughter (she was very young and inexperienced at the time), so costar Richard Widmark straight-up slapped her in the face to get her crying. (Kinski, for her part, never bore him any ill will and said later she knew he was just trying to get a good performance out of her, and that he taught her a lot.)
Fake Nationality: About one million times. Basically, this would show up in any movie set outside England, and even some set inside it.
Bit player Michael Ripper, who appears in so many there's probably a drinking game about him.
There's also a lot of crossover between Hammer girls and Bond girls.
The second Doctor was in several Hammer films; word is he got the part while working on The Viking Queen. And Romana showed up in Vampire Circus.
Benny Hill regular Bob Todd shows up briefly in Scars of Dracula. Try not to think of "Yakety Sax," especially since his scene is basically him chasing the hero out of town for seducing his daughter.
Missing Episode: Hazel Court allowed a topless scene to be filmed for 1959's The Man Who Could Cheat Death. It was only included in prints distributed outside the U.S. and England. It appears this footage has been lost forever, although Court did put a still from it in her autobiography. (Let it never be said that she didn't appreciate her fans.)
Troubled Production: Blood From the Mummy's Tomb, adapted from The Jewel of Seven Stars; Peter Cushing was cast as the lead but had to drop out after a single day's filming due to the hospitalization of his wife. Then five weeks into production (with only one week to go), director Seth Holt had a heart attack and died (some reports saying this was on set) and was replaced by Michael Carreras. On top of all that, star Valerie Leon was devastated when she was told she couldn't attend Holt's funeral.
Unintentional Period Piece: All the episodes of the TV series ''Hammer House of Horror" are set during the era they were filmed, the 1980s, and there are mullets galore.