Svaðilfari is a mythical horse from Norse mythology, known for its immense strength and endurance. It is often associated with the construction of the walls of Asgard, the home of the gods. Svaðilfari was owned by a giant who was tasked with building these walls in exchange for the goddess Freya, the sun, and the moon. In the myth, Loki, the trickster god, transformed into a mare to distract Svaðilfari, preventing the giant from completing the wall on time. As a result, the giant failed in his task, and Loki later gave birth to Sleipnir, an eight-legged horse, who became the steed of Odin.