Lu-Kthu is a Cthulhu Mythos deity created by H.P Lovecraft. It is said to be the Birth-womb of the Great Old Ones,
described as a "A titanic, planet-sized mass of entrails and internal organs. On closer examination it appears a wet, warty globe, covered with countless ovoid pustules and spider-webbed with a network of long, narrow tunnels. Each pustule bears the larva of a Great Old One."