In non-horror roles, he is best known to modern audiences for narrating and as the voice of the Grinch in the animated television special of Dr. Seuss' How the Grinch Stole Christmas! (1966). For his contribution to film and television, Karloff was awarded two stars on the Hollywood Walk of Fame.
Karloff acted in eighty movies before being found by James Whale and cast in Frankenstein (1931). Karloff's role as Frankenstein's monster was physically demanding – it necessitated a bulky costume with four-inch platform boots – but the costume and extensive makeup produced a lasting image. The costume was a job in itself for Karloff with the shoes weighing 11 pounds (5.0 kg) each. Universal Studios quickly copyrighted the makeup design for the Frankenstein monster that Jack P. Pierce had created. It took a while for Karloff's stardom to be established with the public – he had small roles in Behind the Mask (1932), Business and Pleasure (1932) and The Miracle Man (1932). As receipts for Frankenstein and Scarface flooded in, Universal gave Karloff third billing in Night World (1932), with Lew Ayres, Mae Clarke and George Raft.
Karloff was reunited with Whale at Universal for The Old Dark House (1932), a horror movie based on the novel Benighted by J.B. Priestley, in which he finally enjoyed top billing above Melvyn Douglas, Charles Laughton, Raymond Massey and Gloria Stuart. He was loaned to MGM to play the titular role in The Mask of Fu Manchu (also 1932), for which he gained top billing.
Back at Universal, he was cast as Imhotep who is revived in The Mummy (1932). It was as successful at the box-office as the other two films and Karloff was now established as a star of horror films. Karloff returned to England to star in The Ghoul (1933), then made a non-horror film for John Ford, The Lost Patrol (1934), where his performance was highly acclaimed. Karloff was third billed in the Twentieth Century Pictures historical film The House of Rothschild (1934) with George Arliss, which was highly popular. Horror, however, had now become Karloff's primary genre, and he gave a string of lauded performances in Universal's horror films, including several with Bela Lugosi, his main rival as heir to Lon Chaney's status as the leading horror film star. While the long-standing, creative partnership between Karloff and Lugosi never led to a close friendship, it produced some of the actors' most revered and enduring productions, beginning with The Black Cat (1934) and continuing with Gift of Gab (1934), in which both had cameos. Karloff reprised the role of Frankenstein's monster in Bride of Frankenstein (1935) for James Whale. Then he and Lugosi were reunited for The Raven (1935). For Columbia, Karloff made The Black Room (1935) then he returned to Universal for The Invisible Ray (1936) with Lugosi, more a science fiction film. Karloff was then cast in a Warner Bros. horror film, The Walking Dead (1936).