Jotnar, or Jotuns, were giants from Jotunheim, the land of ice and snow, and thanks to Marvel, they’re colloquially known today as frost giants.
Throughout Norse mythology, Odin and the Jotnar – frost giants – constantly battle one another. But what did the frost giants do to Odin to cause him to hate them so much?
Originally, the frost giants didn’t do anything to Odin. It was Odin and his two brothers who first wronged them.
To make the world, Odin, Vili, and Ve killed the first frost giant, Ymir, and used his body to shape the nine realms. This is likely the source of hostility between the two races.
This article further expands on Odin’s first crime against the frost giants and explores the long, complicated relationship between the old adversaries.
It will also explore the relationship between the Aesir and the Jotnar in terms of order versus chaos.
Also, see What Is Ragnarok in Norse Mythology? to learn more.
Why Odin Hated the Jotnar
Unlike Greek and Roman mythology, historians and scholars have few sources of information about Norse mythology. Much of what they have comes from two primary works:
- The Prose Edda
- The Poetic Edda
Other sources of information on Norse mythology come from the Heimskringla, written by the same author of The Prose Edda, and Gesta Danorum, penned by Saxo Grammaticus. 
The Icelandic Sagas and various runestones also provide some further information.
However, that pales compared to the world’s wealth of information on other mythologies, most notably Greek and Roman.
With that in mind, it’s not surprising that there’s no real information about why Odin hated the Jotnar. That could be because the reason is lost to history or because he didn’t hate them.
The Eddas are clear that Odin and his brothers killed the original frost giant, Ymir, but they never clearly say that they did so out of anger or any other emotion*, only that they killed him and made the world from his body.
Throughout Norse mythological tales, Odin is represented as a wise, clever, and intelligent god.
It’s entirely possible that he harbored no ill will toward Ymir (his ancestor, after all) and only killed him because he knew he had to create the rest of the world.
*Note: Some sources claim that Ymir was evil, and the brothers were forced to fight him. Others say that the number of frost giants in the world was growing too quickly and that Odin and his brothers were afraid for their safety. Both of these reasons have merit but are somewhat contested among mythological scholars today. 
Why the Jotnar Hated Odin
Whether Odin hated Ymir and the frost giants is unclear, but one thing is certain. The frost giants certainly hated Odin after he killed their progenitor.
This act led to undying enmity between the two races and resulted in the Aesir – Odin and the other Asgardian gods – and Jotnar fighting constantly throughout the myths.
According to Norse belief, the ultimate battle between the Asgardians and Jotnar will take place at Ragnarok, the end of all things.
At that time, Loki, who is at least half-Jotnar by birth, will join with the giants, Surtr, and the dead of Hel to fight against the Aesir in one final, epic battle, where most beings on both sides of the fighting lines will die.
However, Ragnarok isn’t the only notable interaction between the gods and giants.
Odin, in particular, crossed paths with many frost giants across Norse mythology.
While the popular consciousness often views the gods and giants as adversaries, they sometimes work as allies in these meetings.
However, Odin was manipulative and often sneaky. He had significant interactions and complicated relationships with many frost giants.
The following sections will examine these encounters.
Odin, Hrungnir, and Thor: Why the World Hast Flint
A Jotun with a stone head and heart, Hrungnir was goaded into a race by Odin, who claimed his eight-legged horse Sleipnir was the fastest in the world.
God and the giant raced to the edge of Asgard, and Odin and Sleipnir won. 
Rather than being angry, Hrungnir remained in high spirits, and Odin invited him back to his hall to drink mead and feast.
However, once there, Hrungnir drank too much and boasted that he would kill all of the Aesir, and save two of the most beautiful women, though his plans for leaving them alive weren’t at all noble.
Thor started to kill Hrungnir outright, but Hrungnir challenged him to a duel instead.
The giant protected himself using a stone shield and a whetstone, which he threw at Thor’s head.
Thor’s head, however, was so strong that the whetstone broke into a million pieces, which is why people, even today, can still find flint on the ground.
Thor then made swift work of killing Hrungnir.
Suttungr, Gunnlod, and Odin: Why the World Has Poetry
Suttungr was the Jotun keeper of the mead of poetry, something Odin desperately coveted.
To keep Odin or anyone else from stealing the mead, Suttungr locked it away with his daughter, Gunnlod, inside a mountain.
Through trickery, deceit, and hard work, Odin convinced Suttungr’s brother to share the mead with him. However, Suttungr refused, even after hearing his brother’s pleas.
So, Odin woos Gunnlod through a hole in the mountain until she lets him inside. 
The two become romantically involved, and Odin eventually persuades Gunnlod to let him have a single drink from the mead.
This, of course, is a trick, and when she relents, he gulps the entire cask of mead down. Then, he uses magic to turn himself into an eagle and fly back to Asgard.
Enraged, Suttungr also turns himself into a bird and chases Odin to Asgard.
However, Odin gets there first and safely spits the mead into a cask. However, a few drops fell from his lips along the way, landing on Midgard (Earth). That’s why humans have poetry today.
Vafthrudnir and Odin: The Game of Riddles
The Poetic Edda talks about Vafthrudnir as the wisest giant.
Vafthrudnir played a game of questions and answers with a disguised Odin. In pursuit of the giant’s knowledge, Odin dressed as a human nomad named Gagnrad.
He then used a game of questions and answers to learn how he would die, with Vafthrudnir revealing that Fenrir would swallow the god.
Odin revealed himself to the giant by asking a final, impossible question: “What did Odin say into the ear of his son before he mounted the pyre?”
Vafthrudnir acknowledged he couldn’t answer the question and conceded the game to Odin.
The Aesir Versus the Jotun As an Allegory for Order Versus Chaos
Besides Odin’s slaying of Ymir, there is no apparent reason behind the enmity between the Aesir and Jotnar.
However, their constant struggle symbolizes a more significant theme: order versus chaos.
Ymir sprung fully formed from the ice which appeared after the lands of fire and ice met at Ginnungagap, described in some translations as “a chaotic chasm.” 
He and his frost giant offspring were often considered agents of chaos, whereas the gods were beautiful, intelligent, and wanted to bring order to the world.
Their constant struggle, therefore, was a fight between chaos and order, the two main forces that drive the actions of the universe.
In many ways, their ongoing battle allowed the Norse people to make sense of the chaotic world around them.