Garmr

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

The Poetic Edda poem Grímnismál mentions Garmr:

:The best of trees | must Yggdrasil be,

:Skíðblaðnir best of boats;