Loki is the god of mischief, guile, cunning and trickery in Norse mythology. He is also seen as the personification of chaos and evil as well as being the Lord of Lies. At one point in time he was also known as being the God of Fire.
He is portrayed as a scheming craven who cares only for self-preservation and guilty shallow pleasures. He’s depicted as being playful, malicious, and at certain times even helpful, but he’s always irreverent, nihilistic and impetuous.
Loki possesses the ability of changing his entire appearance (called Shapeshifting) and even his gender, although he had to borrow Freyja's magical cloak at times to change into a falcon. He has been known to take the form of a mare, salmon and an old Jotun woman
Once, Loki changed himself into a mare, and he bore the son of a horse. This eight-legged horse is called Sleipnir, and became the favorite horse of Odin. Loki also has many monstrous children, namely Hel, Fenrir, and Jörmungandr. He and his children became enemies of the gods in Ragnarok.
Loki is a murderer. He cut off the hair of Thor's wife, Sif, but then replaced it, he tricked a giant into building the defensive walls of Asgard, stole Freyja's necklace, helped Thor rescue his hammer Mjolnir, gave the goddess Iðunn to a giant, then rescued her, etc. He was blamed for the death of the god Baldur, using the blind god Höðr's hands. In a poem called Lokasenna (Loki's Arguments), he insulted all the gods and goddesses. For this, he was bound to rock with the intestines of his son, until Ragnarok. Loki was punished many times in ways including; having a venomous snake drip venom into his eyes and he had his lips sewn together with a leather thong by the dwarves.