Bel Shamharoth is a chthonic god of the Underworld and the Dungeon Dimensions of Discworld who is drawn — with extra tenacles — greatly from the works of HP Lovecraft and is encountered in the first Discworld novel, The Colour of Magic.
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/discworld/characters/bel-shamharoth/en.wikipedia.org.md