A fierce monstrous dog who guards the entrance to Helheim, the Norse realm of the dead. It has four eyes and a chest drenched with blood. Garm, whose name means "barking," is mentioned in both the 'Poetic (or Elder) Edda' and the 'Prose (or Younger) Edda'. He was the hound of Hel, the fearsome goddess of the underworld. He was kept chained up in a place called Gnipahellir, a cave at the entrance to Niflheim, the cold, forbidding land of the dead. Physically, he towers as tall as a large pony or moderate-sized horse -- his shoulder rises some seventeen hands above the Niflheim ice, his head a good four hands higher than that. The thick fur on his haunches and the heavy pads of his toes allow him to be as uncaring as anyone -can- be to the chill of his home, though now and again even he must chew the ice from between his toes. Otherwise, the faint russet glow of his gaze looks, and judges, and does not cruelly care whether or not his decisions are going to be amenable for -you-...
It was believed that at the time of Ragnarok, the battle that would signal the end of the world, Garm would break loose from his chain and fight on the side of the evil giants and monsters against the gods. Garm would attack the god Tyr and kill him, and in turn be killed by him. Garm is often equated with the wolf Fenrir.