Hyrrokkin

Then Odin’s horse Sleipnir was fetched and led forward
and Hermod mounted this horse and galloped away. So the Æsir
took Baldr’s body and carried it to the sea. Hringhomi was the
name of Baldr’s ship. It was the biggest of all ships. This the Æsir
planned to launch and perform on it Baldr’s funeral. But the ship
refused to move. So they sent to Giantland for a giantess called
Hyrrokkin. And when she arrived, riding a wolf and using vipers
as reins, she dismounted from her steed, and Odin summoned
four berserks to look after the mount, and they were unable to
hold it without knocking it down. Then Hyrrokkin went to the
prow of the boat and pushed it out with the first touch so that
flame flew from the rollers and all lands quaked. Then Thor
became angry and grasped his hammer and was about to smash
her head until all the gods begged for grace for her. Then Baldr’s
body was carried out on to the ship, and when his wife Nanna
Nep’s daughter saw this she collapsed with grief and died. She was
carried on to the pyre and it was set fire to. Then Thor stood by
and consecrated the pyre with Miollnir.


- Prose Edda, Gylfaginning