in Welsh tradition, the trusted hound of Prince Llewellyn the Great of Wales. Having been left to guard his master's infant son, Gellert killed a wolf that attempted to attack the child. Llewellyn, returning home to find the baby missing and Gellert's muzzle stained with blood, assumed that the dog had destroyed his son, and stabbed it. He later found the child unharmed beneath the overturned cradle, with the wolf's corpse beside him. The remorseful prince caused Gellert to be honourably buried on Mt. Snowden, and he named the place Beddgelert (Grave of Gellert).

The story, associated now with the historical Prince Llewellyn, is a late Welsh version of an ancient Indian folktale recounted in the Sanskrit Pañca-tantra. The legend is found in various forms in many European countries. It also exists in the Persian, Hebrew, and Buddhist traditions.