The Star-spawn of Cthulhu.

The star-spawn of Cthulhu (or Cthulhi) are beings who arrived on Earth with Cthulhu. They resemble Cthulhu and may be his progenies. Like Cthulhu, they can mutate their shapes, but always retain their master's distinctive outline. After coming to Earth, the star-spawn built a great basalt city called R'lyeh on an island in the Pacific Ocean. They warred briefly with the Elder Things, but thereafter established a treaty. When R'lyeh sank, the star-spawn became trapped beneath the sea with Cthulhu (nonetheless, a few of his spawn may still be free).