Loki is a mysterious contradictory spirit perhaps the ultimate trickster. Loki is usually classified as a Jotun (giant) but was conceived when lightning (his father) struck a leafy oak (his mother) and so may be some kind of primordial fire spirit. His name is related to an Old High German word meaning "shooting star" Loki was born from the spark of life but his own children include the goddess of death and the wolf of doom.
Loki lives among the Aesir spirits and is Odin's blood brother. He is Thor's traveling companion, ostensibly his friend. Yet he conspires against them and is responsible for the death of Baldur. At the same time he is instrumental in obtaining many of their most precious tools and attributes. Loki constantly leads the Aesir into danger and then proceeds to rescue them as with the myth of Idunn's apples or the theft of Thor's hammer. Loki's motives and loyalties are never clear. Part of this confusion is because Norse mythology was committed to paper by later Christian commentators who identified Baldur with Christ. Extending the metaphor Loki was identified with Judas or Satan. It is difficult if not impossible to find sympathetic portrayals of Loki. (And yet with Loki there is always an exception: in a traditional ballad from the Faeroe Islands after Odin and Hoenir another Aesir spirit fail Loki rescues a young boy from a troll in response to prayers directed to him by the boy's parents.)
Loki is more than a trickster and a plotter, he is a skilled inventor artisan and craftsman. He is a font of obscure knowledge nosy and extremely observant. He has a malicious streak and a vicious cutting humor although he is also the only one able to make the goddess Skadi laugh following the death of her father.
Loki is a master shape-shifter. He can appear in any guise. Loki who enjoyed sexual relations with many of the Norse goddesses is allegedly very handsome and charming when he wishes to be.