Loki is a character from the Marvel Cinematic Universe. He is the God of Mischief and the biological son of Odin, King of Asgard. Abandoned at birth, he was found by Odin and raised as an Asgardian prince. However, Loki's true heritage was revealed when Thor was banished to Earth, leading to Loki's attempt to declare war on the Frost Giants and ultimately his downfall. He has a complex history, including faking his death and taking Odin's place as King of Asgard, and ultimately being killed by Thanos. Loki's character has been portrayed by Tom Hiddleston in various Marvel films and the Disney+ series "Loki."
Sources: Marvel Cinematic Universe Wiki: Loki Marvel.com: Loki Wikipedia: Loki (TV series)