Loki is a Marvel Comics villain who often serves as the arch-nemesis of his adopted brother, the superhero Thor.
Loki is the son of Laufey, king of the Frost Giants, and sworn enemy of Odin. After killing Laufey, Odin finds Loki hidden away and takes pity on him (Laufey was ashamed of how undersized Loki was and kept him out of sight). Odin brings Loki to Asgard and raises him alongside his own son, Thor.
There is a tremendous amount of resentment between the brothers. While Thor is strong and tenacious, Loki is a powerful sorcerer. Loki is also a mischievous trickster who doesn't fit in with the ideals of Asgard, and spends much of his time plotting a takeover.
His character, as portrayed by Tom Hiddleston in the Marvel Cinematic Universe (MCU), has been heavily featured in the Thor and Avengers movies as well as in his own show, Loki (2021–2023), and has become hugely popular as a result. Over the course of his entire arc, Loki undergoes one of the biggest character shifts in the entire MCU.
When discussing the comic book series, Loki: Agent of Asgard (2014–2015), writer Al Ewing confirmed Loki's bisexuality and promised to explore it in the series. Later on in the Loki series, Hiddletston’s Loki makes a direct reference to having had many affairs with both princesses and princes.
Kate Herron, a producer and director of the series, shared her thoughts about what Loki's bisexuality meant to her as a bi woman:
From the moment I joined @LokiOfficial it was very important to me, and my goal, to acknowledge Loki was bisexual. It is a part of who he is and who I am too. I know this is a small step but I’m happy, and heart is so full, to say that this is now Canon in #mcu #Loki 💗💜💙
— Kate Herron (@iamkateherron) June 23, 2021