Updated: Nov 24, 2021
So since the marvel show Loki wrapped up on Disney plus almost two weeks ago (July 14th) I wanted to take a look at the character as portrayed in actual Norse mythology, not just in Marvel cinematic universe (MCU).
So lets start with what the MCU got right (which is quite a lot so I'll focus on the major points). So whilst there is some debate about Loki's title in mythology it is widely accepted that he is the trickster god of mischief, other accounts call him a deity of fire but these seem to be linked to the origin of his name rather than how he acts in the mythology. Loki is also born of a Jötunn like in the MCU however his mother Laufey (changed to his father in the MCU) was considered to be an Asynjar (Goddess) which would explain why Loki is a part of the Aesir (the Gods).
Like in the MCU Loki in mythology is not exactly as simple as a good or bad person, he uses his wit and cunning to get the Gods out of all sorts of trouble but then he also uses it to get them into mischief. It is believed that Loki is more of a force of chaos, only really helping when it benefits him and looking out for his own interests above anything else.
One of Loki's main powers is shapeshifting and they use this multiple times in the mythology, for example when Loki and Thor had to pretend to be handmaidens to get Mjolnir back from a Jötunn (weird story I know, best to just go with it). With this power comes one of the biggest questions about Loki, are they gender fluid? Now I don't have an answer for this because there are so many conflicting stories and interpretations but you might notice I used the pronoun they because I believe that if anyone in mythology is gender fluid it would be Loki. You might not agree and that's completely fine, however I would draw your attention to the time that Loki apparently shapeshifted into a mare and gave birth to the eight legged horse Sleipnir who would become Odin's steed.
Now my favourite thing about Loki in mythology isn't actually the trickster god himself but his children of which he had six. I've already told you about Sleipnir but there is also Narfi and Vali who they had with their Aesir wife Sigyn. However his three most interesting children come from his time with Angrboda, a Jötunn giantess, and these consisted of Hel, the ruler of the eponymous Helheim, Fenrir, a giant wolf of great power, and finally Jörmungandr (depicted below), the world serpent. I won't go in depth about those three today but lets just say that each one was feared by the Aesir for their immense power.
Overall Loki is a confusing figure to understand, their motives are never fully clear and they appear to just be an agent of chaos and self gain, never truly picking a side until Ragnarok where it is said they will march on the Aesir with an army of the dead but this could be justified by the mistreatment of them throughout Norse Mythology.