For 10 points, name this enemy of the Midgard Serpent who owned the hammer Mjolnir, the Norse god of thunder.
With the help of a servant, this man defeated a stone-hearted clay giant. That battle resulted in this god requiring help from the seer Groa in removing a whetstone from his head. This god gained the service of Roskva and the aforementioned servant Thialfi when the latter broke the thigh-bone of one of his goats. In addition to killing the giant Hrungnir, this god once fished his mortal enemy out of the ocean and failed to lift its paw when it assumed the form of a cat in the realm of Utgard-Loki. For 10 points, name this enemy of the Midgard Serpent who owned the hammer Mjolnir, the Norse god of thunder.
With the help of a servant, this man defeated a stone-hearted clay giant.
Thor