Spawn of Hastur

The Spawn of Hastur are a sapient species of giant aquatic creatures which dwell in the mysterious Lake Hali and serve their god, Hastur.

Biology
The Spawn of Hastur are carnivorous and capture prey with eight long grasping tentacles. The prey is either crushed by the tentacles or brought into the monster's sac-shaped body to be swallowed whole.

Despite being primarily aquatic, these creatures are capable of venturing onto land and even flying over short distances by unknown means. They can also perform certain kinds of magic spells.