Garmr

In Norse mythology, Garmr or Garm (Old Norse "rag") is a dog associated with both Hel and Ragnarök, and described as a blood-stained watchdog that guards Hel's gate.

Attestations

Poetic Edda

The Poetic Edda poem Grímnismál mentions Garmr:

One of the refrains of Völuspá uses Garmr's howling to herald the coming of Ragnarök:

After the first occurrence of this refrain the Fimbulvetr is related; the second occurrence is succeeded by the invasion of Jötnar (giants) in the world of gods; after the last occurrence, the rise of a new and better world is described.

Baldrs draumar describes a journey which Odin makes to Hel. Along the way he meets a dog.

Although unnamed, this dog is normally assumed to be Garmr. Alternatively, Garmr is sometimes assumed to be identical to Fenrir. Garmr is sometimes seen as a hellhound, comparable to Cerberus.

Prose Edda

The Prose Edda book Gylfaginning assigns him a role in Ragnarök:

Etymology

Bruce Lincoln brings together Garmr and the Greek mythological dog Cerberus, relating both names to a Proto-Indo-European root *ger- "to growl" (perhaps with the suffixes -*m/*b and -*r). However, as Ogden (2013) notes, this analysis actually requires Cerberus and Garmr to be derived from two different Indo-European roots (*ger- and *gher- respectively), and in this opinion does not establish a relationship between the two names. However, the two roots are similar enough that a connection can still be argued.