(Music: Skuggsja - Kvervandi)
In Norse mythology Hel (Goddess of the Underworld), Fenrir (wolf) and Jormungand (serpent) are children between Loki and the giantess Angrboda. Learn more about them here
(And yes, there is no Sleipnir here, he was born another interesting way and as for me he doesn't belong here)
Art prints with this piece available on society6
Jörmungandr, or the Midgard Serpent, is much more of a monster than his siblings. He is so large that he surrounds all of Midgard (hence his nickname), and it is said that when Ragnarok happens, Jörmungandr will poison the ocean and cause massive tidal waves, and he will kill the god Thor.
Realms of Dead in Norse mythology are even weirder. There is of course Hel, where people who died plainly (like illness or age) go. There is Ran where people who drowned go and Völkfangr where those who died in battle and get cherry-picked by Freya go. Odin's Valhall gets those who died in battle and do not qualify for Freya. Maybe Frey wants cold, methodical soldiers and Odin wants loud, boisterous warriors.