The Sleeping Beast is a creature that dwells in a pool deep within the House of Darkness and was featured in He-Man and the Masters of the Universe.
According to its mistress Shokoti, it has the power to envelop Eternia in living darkness. She planned to sacrifice He-Man, Ram Man, and Battle Cat to the beast when it awoke, but Stanlan managed to overcome his fear of Shokoti and used the Sword of Power to save them. The Sleeping Beast easily chewed up a stone altar that Ram Man sent flying at it, but He-Man was able to defeat it by shoving a giant statue of Shokoti into its pool, melting the statue as the beast sank back into the murky depths.