Thursday marks the 125th birthday of H.P. Lovecraft, arguably the most towering figure in the horror-fiction genre and one of the most influential writers of the 20th century.

His influence can be felt just about anywhere in pop culture, from film (the works of director John Carpenter, for instance) to comic books (“Watchman” creator Alan Moore and “Hellboy” creator Mike Mignola are two examples) to television (Lovecraft was a character in an episode of “Supernatural,” and Rod Serling adapted some of his stories for "Night...