The surprising reason Christopher Lee's Frankenstein looks so different than other portrayals of The Creature
The 1957 film took a new approach to the monster.

Audiences have enjoyed various iterations of Frankenstein, each film providing a new stitch in the monster’s tapestry. This story has come a long way from Mary Shelley’s 1818 novel, and with any luck, audiences will be able to enjoy more iterations for years to come.
But while the first few Frankenstein films kept a fairly tame image, The Curse of Frankenstein broke any mold previously established. During an interview with the BBC, Patricia MacCormack, a professor of continental philosophy, called the 1957 film "the first really gory horror film, showing blood and guts in colour.”
The monster, played by Christopher Lee, had a much more gruesome appearance than his Karloff counterpart in the original 1931 film. According to the article, Lee had previously stated that this transformation wasn’t an artistic choice; it was borne out of necessity. The actor said that Karloff’s makeup for the monster had been copyrighted, so Hammer Productions was forced to create its monster from scratch.
The extra effort was well worth it; The Curse of Frankenstein terrified and enthralled audiences. However, senior film lecturer Dr. Ni Fhlainn argued that the more gruesome the portrayal of the Shelley character, the further we strayed from the original vision of Frankenstein.
"It's a frustration," says Dr Ni Fhlainn. "If you love the novel, it wasn't Shelley's intention to create something that goes out and mindlessly kills, but I can see how this can be useful in films...When the monster is seen as non-human, it's very easy to dismiss him and kill off. When he's more human, it's very difficult to do that."