In Norse mythology, Skadi was daughter of Thiazzi of the Hrimthurssar, the frost giants who inhabited Jotunheim. They all were enemies of the gods. Skadi (also Skade) was wife to Njord, the Vanir god of the seas, sailors and fishermen.
In Norse ancient beliefs, the ‘Hrimthurssar’ giants had names: ice ‘thiazzi’, frost ‘thrym’, ‘destruction skade’, glacier ‘jokull, cold ‘frosti’ and many others. They represented the changing seasons, harshness of long winters of northern climates and the coming of the eternal night and cold. The Hrimthurssar were descendants of Ymir, the first great giant, formed from the ice and fire that existed at the beginning of time. Ymir represented, in part, the numbing cold of the Artic region.
After Thiazzi, father of Skadi died , she had to decide about her life. She went to Asgard, the home of the gods to choose a husband. She and god Njord could not live happily together. Skadi did not like Noatun (‘shipyard’), where god Njord lived. Njord , on the other hand, did not like the severe cold of Thrymheim, which was Skadi’s home. So they decided to separate.
In one story ‘Loki’s Punishment’, the giantess Skade placed a venomous serpent over the head of the trickster god, Loki. This goddess symbolizes so terrible cold that she can be touched only briefly by the warm summer sun (Njord) and the trickster Loki’s hearth fire, one myth says.
Snorri Sturluson’s Prose Edda explains that Skadi’s father was killed by the gods after stealing the golden apples of Idun. When his daughter learned about his death, she was furious; equipped with her shining armor and weapon and marched across Bifrost (the rainbow-like bridge leading from Midgard to Asgard) to face the gods responsible for her father’s death..
It was forbidden to steal Idun’s magic apples, which kept all the Asgard’s gods young. After she arrived, they asked Skadi – according to the Norse custom - if she would take gold in payment for her father’s death.
She explained that she was in possession of all the gold she ever needed. When her grandfather Olvaldi had died, he left much gold to his sons and one of them was her own father Thiazzi; now she had this gold. Instead, Skaldi wanted to have a husband from among the gods.
The gods agreed to the giantess’ demand but there was one condition: she had to choose her husband by pointing to the feet that she liked best, and so she did.
However, she also had one condition. The gods must make her laugh because she was still very angry. Laughing could make her frozen heart warmer.
The unusual deal was struck. The gods placed themselves behind a curtain and only their feet were clearly visible. Immediately, one pair of feet made Skadi very interested – the feet of god Njord. So he took Skadi to his warm, seashore home but she did not like it. Njord, then, moved with her to Thrymheim, her cold, sunless world with constantly blowing wind, howling of the wolves and severe cold.
To save their marriage, these two decided to spend nine days in Njord’s world and nine in Skadi’s. Skadi spent much more time in her cold world using her arrows to kill bears and wolves.
In "Ynglingasaga" of Snorre Sturlassons "Heimskringla" dated to 1230, is said that the giantess Skadi could not live with Njord, so later, she married Odin, with whom she had many sons. One of them, Sæmingr, was the ancestor of the kings of Norway.
Snorri writes about Skadi, a jötunn and a "fair maiden":
“…The giant-queen of rock and snow,
Who loves to dwell on earth below,
The iron pine-tree's daughter, she
Sprung from the rocks that rib the sea,
To Odin bore full many a son,
Heroes of many a battle won…."