This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Garmr (Norse)
In Norse mythology, Garmr or Garm is a wolf or dog associated with both Hel and Ragnarök, and described as a blood-stained guardian of Hel's gate.The etymology of the name Garmr remains uncertain. Bruce Lincoln brings together Garmr and the Greek mythological dog Cerberus, relating both names to a Proto-Indo-European root *ger- "to growl".
Old Norse literature often portrays Garm as a monstrous hound with blood-stained fur, a testament to its menacing presence. Its harrowing features and characteristics serve as a reminder of the inevitability of death and the terrors of the underworld. As a result, Garm’s dark nature has fascinated and inspired artistic minds for generations.