Hamskerpir and Garðrofa

In Norse mythology, Hamskerpir and Garðrofa are a pair of horses who sired Hófvarpnir, the horse ridden by the goddess Gná. Hamskerpir and Garðrofa are attested in the Prose Edda, written in the 13th century by Snorri Sturluson.

Attestations
In chapter 35 of the Prose Edda book Gylfaginning, High provides brief descriptions of 16 ásynjur. High lists Gná thirteenth, and in his description provides a stanza that gives Gná's horse Hófvarpnir's parents as Hamskerðir and Garðrofa:
 * "I fly not
 * though I fare
 * and move through the air
 * on Hofvarpnir
 * the one whom Hamskerpir got
 * with Gardrofa."

Theories
John Lindow says that the name Hamskerpir does not have an obvious meaning, but that Garðrofa may mean "fence breaker." Lindow adds that two horses are otherwise unknown from any other source, and that the myths surrounding them have not survived.