In Norse mythology, Skínfaxi and Hrímfaxi are the horses of Dagr (day) and Nótt (night). The names Skínfaxi and Hrímfaxi are bahuvrihis, meaning "sheen mane" and "rime mane" [or "frost mane"], respectively. Skinfaxi pulled Dagr's chariot across the sky every day and his mane lit up the sky and the earth below.
The myth of Skinfaxi is believed to originate in the Nordic Bronze Age religion, for which there is strong evidence of beliefs involving a horse pulling the sun across the sky. The Trundholm sun chariot is drawn by a single horse, and was possibly imagined to be pulled back across the sky west to east by a second horse.