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.
Then Óðinn rose, | the enchanter old,
And the saddle he laid | on Sleipnir's back;
Thence rode he down | to Niflhel deep,
And the hound he met | that came from hell.
Bloody he was | on his breast before,
At the father of magic | he howled from afar;
Forward rode Óðinn, | the earth resounded
Till the house so high | of Hel he reached.
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.