Herrauðr, Herraud, Herröðr, Herruðr, Herrud, Herothus or Heroth is a legendary earl of Götaland or king of Sweden, who appears in several medieval legends, in particular those relating to Ragnar Lodbrok (e.g. Tale of Ragnar's Sons, Tale of Ragnar Lodbrok, Krákumál and Gesta Danorum, book 9). He also has a saga of his own in Bósi and Herrauðr's saga.
His main role in the sagas is as the father of Þóra Borgarhjǫrtr who gave his daughter one or two small lindworms which grew so big that he had to promise her to the man who could slay the serpent(s). Ragnar Lodbrok took on himself to liberate the girl and became her husband. Bósi and Herrauðr's saga works as a prequel describing the origin of the lindworm.
In Krákumál, the dying Ragnar Lodbrok sings that a more famous earl than Herröðr had never steered his longship into a harbour [1].
Bósi and Herrauðr's saga tells that Herrauðr was the son of king Ring of Östergötland and the nephew of Gautrekr, the king of Västergötland. Herrauðr's grandfather was Gauti, a son of Odin.
Herrauðr's father Ring preferred his illegitimate son Sjóðr to Herrauðr. When Herrauðr's best friend Bósi was outlawed, the two friends set off to spend some years pillaging as Vikings. Back in Östergötland, Sjóðr forced Bósi's father to pay money in compensation for Bósi's crime, so when Sjóðr and Bósi met in Wendland the two started fighting and Sjóðr was killed. When the two friends returned to Östergötland, Ring refused to reconcile with Herrauðr and instead he incarcerated Herrauðr and Bósi and intended to execute them.