Biography
Boris Karloff (November 23, 1887 – February 2, 1969), whose real name was William Henry Pratt, was an English-born actor who emigrated to Canada in 1909. Karloff is best remembered for his roles in horror films and his portrayal of Frankenstein's monster in Frankenstein (1931), Bride of Frankenstein (1935), and Son of Frankenstein (1939). His popularity following Frankenstein was such that for a brief time he was billed simply as "Karloff" or "Karloff the Uncanny". His best-known non-horror role is as the Grinch in the television special of Dr. Seuss’s How the Grinch Stole Christmas!. Description above from the Wikipedia article Boris Karloff, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Known For

Frankenstein
The Monster

Scarface
Gaffney

The Old Dark House
Morgan

Lured
Charles van Druten

Bride of Frankenstein
The Monster

The Mummy's Hand
Kharis (archive footage / uncredited)

How the Grinch Stole Chri...
Narrator / The Grinch (voice)

The Mummy
Imhotep, alias Ardath Bey

Black Sabbath
Gorca (segment "The Wurdalak")

The Terror
Baron Victor Frederick Von Leppe