(Alternate spelling: Hymer)
A giant of Norse mythology, Hymir was a giant of frost and the sea. He was married to the giantess Hrod, and the two lived in Egil, near the edge of the sky. Hymir owned a gigantic magical cauldron which he used to brew vast amounts of beer in -- amounts suited to get even the Gods drunk, considering that the cauldron had a depth of several miles. Since Norse gods weren't exactly the boring, chaste abstainers preaching non-violence we know from modern Western religions, they needed such a giant cauldron for the nightly drinking parties at Valhalla, where gods, Valkyries and dead Vikings would spend the nights drinking and carousing (after spending the day beating the living shit out of each other, preparing for Ragnarok).
So the gods sent out Thor, the Norse god of thunder, to get Hymir's magic cauldron. The god made a bet with Hymir: If the two went fishing and Thor could get a bigger catch than the giant, the cauldron would be his. Hymir had three of his giant oxen butchered, and the two used the three heads as bait. Hymir caught two whales, but Thor was hard to beat: He caught Jormungand, the Midgard Serpent, itself (the cowardly giant cut Thor's fishing line, afraid the serpent would kill them both). Not one to accept he was beaten, Hymir gave Thor a second challenge: To break his magical (and all but indestructible) cup. For reasons unknown, the giant's wife Hrod let Thor know that Hymir's head was harder than the cup, so by smashing the cup against the giant's thick skull, Thor won the giant cauldron and brought it back to Valhalla.
Hymir plays a major role in Ragnarok. He has a ship, Naglfar, made entirely from the nails of the dead. The flood that comes just before Ragnarok sets the stranded ship free, and all the giants board it with Hymir as the ship's commander. Thus he is responsible for bringing the giants to Vigrond, the battlefield on which the final battle between gods and giants is fought. Like all the other giants (and the majority of the gods), Hymir is killed during the battle.