Garm is a watchdog who guards the entrance to Hel which is ruled by Hela. The living are allowed to pass while the dead are not. Greyval Grimson and Balder both pass her on their way into Hel. When Thor tried to take some mortal souls from Hel, Garm attacked. She was knocked unconscious by Mjolnir. She was again defeated by Thor in a later issue when Thor donned the Destroyer Armor. When the Hulk and Balder entered Hel to save Thor, they teamed up and managed to subdue Garm.
Major Story Arcs
When Loki, reborn as a child, needed to get into Hel to see Hela, he brought along Hel Wolf to deal with Garm. While the two fought Loki ran past. When he returned Garm informed he didn't need to sneak past, being a God he was welcomed. Loki embarrassed took his leave with Hel Wolf not knowing that the two dogs had mated.
Around Yule Time Loki receives a gift from Hela, a litter of demon puppies, the result of Hel Wolf and Garm's meeting. Along with the package is a note from Garm stating the offspring were Loki's responsibility because Hel Wolf's death was part of Loki's doing. Of this litter Thori is the most famous, due to his fowl mouth, tendency to want to murder, and the fact that out of the seven puppies he was the one Loki adopted.