The most famous monster in movie history wasn't even named in the opening credits. Where the actor's name should have been, Universal printed a question mark. His real name was William Henry Pratt, born in London in 1887. His family expected him to become a diplomat like his older brothers. Instead he sailed to Canada, worked on farms and joined traveling theater troupes. Along the way he picked a stage name: Boris Karloff. For years, Hollywood barely noticed him. He played dozens of bit parts in silent films and drove a truck between jobs to pay the rent. Then in 1931, director James Whale spotted him in the Universal lunchroom and saw something in that face. He asked Karloff to test for the creature in Frankenstein. Makeup artist Jack Pierce spent hours every morning building the flat head, the heavy brow and the neck bolts. Karloff took out a dental bridge so one cheek would sink in. He wore heavy boots and a stiff, padded suit under hot studio lights. The film was a sensation. Nearly 44, the man behind the question mark was suddenly a star. He never forgot those brutal hours. In 1933 he became one of the founding members of the Screen Actors Guild, fighting for fairer treatment of actors. Off screen he was gentle, soft-spoken and adored children. And here's the twist. In 1966, at 79, he narrated a cartoon and voiced a green, grumpy fellow who hated Christmas: the Grinch. The record won him a Grammy. One catch: he didn't sing "You're a Mean One, Mr. Grinch." That deep voice belonged to Thurl Ravenscroft, the voice of Tony the Tiger. Grrreat casting. Hollywood's scariest monster ended up best loved for stealing Christmas, and giving it back. Disclaimer: Based on biographies of Boris Karloff and film history accounts. Some details, like makeup times, vary by source. Photos: Karoly Grosz (1931 Frankenstein poster), public domain; unknown photographer (Karloff, 1913), public domain; Universal Studios (1931 lobby card), public domain; NBC Television (Karloff, 1961), public domain; via Wikimedia Commons