Hati and Sköll are the children of Fenrir and as such the grandchildren of Loki. The two wolfs chase Sól and máni, the iterations of the Sun and moon respectively, in their horse drawn chariots. It’s said that when the two wolfs cross paths, and catch and destroy their quarry of eons, that Ragnarök, the Norse doomsday or end of the world, will begin and their farther ,Fenrir, will be released from his mountain dungeon, he will then kill Odin and afterwards Fenrir is himself killed by Odin’s son, Vidarr.