Loki is one of the major deities in Norse mythology. He is a son of the giant Farbauti and the giantess Laufey. He is regarded as one of Aesir, but is on occasion their enemy. He is connected with fire, trickery, and magic and is able to assume many different shapes (horse, falcon, fly). He is crafty and malicious, but also heroic. Over time he becomes disliked by many of the other gods. Loki's wife was Sigyn, the goddess of fertility and faithfulness. She bared two of Loki's children, Narfi and Vali. Loki also had children with Angrboda, a giantess. She birthed Jörmungandr, a giant sea serpent, Fenrir, a giant wolf, and Hel, the ruler of the realm of the dead who is described as half alive and half dead. Loki also tried his hand at motherhood, when he transformed himself into a mare and birthed Slepnir, the 8-legged horse, and child of the stallion Svadilfari.