Hrungnir was the strongest of the Norse giants — a mighty jötunn with a heart, head and shield of stone, who dared to race against Odin, drank himself into a boasting rage in Asgard, and met his end in a famous duel with Thor, in one of the great single combats of Norse myth. His battle with the thunder-god is a tale of stone against hammer, of boasting giant against the gods' mightiest champion.
The Strongest of Giants
Hrungnir (Old Norse Hrungnir) was reckoned the mightiest and strongest of all the jötnar, a giant of stone — for it was said that his head and his heart were both made of hard stone, and he bore a great stone shield and wielded a massive whetstone (or hone) as his weapon. He rode a powerful horse named Gullfaxi (“golden-mane”), swift and strong, of which he was very proud.
The Race with Odin
Hrungnir's downfall began with a boast. Odin, riding his eight-legged steed Sleipnir, came upon Hrungnir and the two fell to arguing over whose horse was the better. They raced — and Hrungnir, in the heat of the chase, galloped right through the gates of Asgard before he realised where he was. The gods, in courtesy, invited the giant to drink; but Hrungnir drank deeply, grew drunk and boastful, and began to threaten the gods, declaring he would carry off Valhalla itself, sink Asgard, kill all the gods and carry away the goddesses Freya and Sif. The gods, weary of his drunken threats, called for Thor.
The Duel of Stone and Hammer
Thor arrived in a fury, ready to kill the giant on the spot — but Hrungnir, being unarmed in Asgard, challenged him instead to a formal duel at the border, and Thor, bound by honour, agreed. The terrified giants, knowing all depended on their champion, built an enormous clay giant named Mökkurkálfi to stand beside Hrungnir and frighten Thor. When the duel came, Hrungnir hurled his great whetstone at Thor just as Thor threw his hammer Mjölnir; the hammer and the whetstone met in mid-air, and the whetstone shattered — but a piece of it flew into Thor's head and lodged there. The hammer flew on and smashed Hrungnir's stone skull, killing him. The giant fell, and one of his enormous legs came down across the fallen Thor, pinning him to the ground.
The Pinned God and the Mighty Child
Thor lay trapped beneath the dead giant's leg, and none of the gods could lift it — until Thor's son Magni, only three nights old, came and heaved the limb off his father with ease, freeing the strongest of the gods where all the others had failed. The fragment of whetstone, however, remained lodged in Thor's head forever. Hrungnir endures as the archetype of the mighty stone-giant brought down by the thunder-god — the strongest of the jötnar, whose boasting led him to a duel he could not win, and whose death in single combat with Thor became one of the most celebrated battles in Norse myth.
The strongest of all giants, with a heart and head of stone, hurled his whetstone at the thunder-god — and though a shard lodged forever in Thor's skull, Mjölnir shattered the stone head and laid the boaster low.