Garm
Garm is a monstrous wolf to rival that of Fenrir, who keeps guard at the entrance to Nifelheim, to keep the dead where they belong until his mistress Hel says otherwise. The origin of Garm is unknown; some say he is the son of Odin's wolves Geri and Freki who Hel took and raised as her own in revenge for what Odin did to her bother Fenrir. Other says he is the son of Fenrir, and some even say he is Hel#s son.
He is the personification of fear, and ate Sol and Mani at Ragnarok in an attempt to stop time from turning.