Hringhorn was the name of Balder’s ship, and it was the largest of all ships. The gods wanted to launch it and make Balder’s bale-fire thereon, but they could not move it. Then they sent to Jotunheim after the giantess whose name is Hyrrokken. She came riding on a wolf, and had twisted serpents for reins. When she alighted, Odin appointed four berserks to take care of her steed, but they were unable to hold him except by throwing him down on the ground. Hyrrokken went to the prow and launched the ship with one single push, but the motion was so violent that fire sprang from the underlaid rollers and all the earth shook. Then Thor became wroth, grasped his hammer, and would forthwith have crushed her skull, had not all the gods asked peace for her.

- Prose Edda (The Fooling of Gylfe, XV)