After this man's death, the toe of Aurvandill is made into a star.
When we first meet this figure, he is introduced as being inquisitive  about a man riding a horse with "a golden helmet riding sky and sea."  After this man's death, the toe of Aurvandill is made into a star. He  refuses to fight in front of the Aesir and eventually does battle in  Griotunagardar. He is described as having a triangular heart made of  stone, and he uses a (*) whetstone as a weapon. After his defeat, the  sorceress Groa ineptly fails to completely revitalize this figure's slayer, who  had his feet freed by Magni once this dude was dead. For 10 points, identify  this jotun slain by Thor.
When we first meet this figure, he is introduced as being inquisitive  about a man riding a horse with "a golden helmet riding sky and sea."  
Hrungnir