The origin of the representation of a severed horse head as an omen of death comes from the 1969 novel The Godfather, where a severed horse head is stealthily placed upon the bedpost of movie producer Jack Woltz, the horse's owner, while he is asleep. He immediately understands this death threat from the mafia as a means to convince him to cast Don Corleone's godson as lead star in his movie. This scene was adapted to the film of the same name released in 1972, and became iconic for its brutality and controversy since a real horse head was used.
The English name of the enemy is a reference to Mister Ed, an American sitcom about a horse that could talk.
Four floating severed horse heads appear in the stables of the Ruined Mansion. They lie in wait, suddenly charging when the player approaches. The last one hangs from the ceiling and flies at Simon rather than attacking at ground level.