Loki from the Marvel Universe is the counter-part of the Joker from DC Comics. The Joker is one of the most likeable villains of all time, according to several lists.
The representation of Loki in the comics makes him a fun villain with a humorous side.
One of the reasons why Loki is so popular is because he's based on a character with the same name from Norse mythology.
Through the years, several villains from the Marvel Universe have died and others replaced them. However, Loki is an exception. He continues to haunt the Avengers and Thor all the time.
Loki was presented by Tom Hiddleston who did a great job making the villain ruthless and likeable at the same time.
One of the powers of Loki is using illusions to trick people. He is originally a trickster god who manages to fool even Thor and Odin.
Loki is not the biological brother of Thor. He has a far darker story that ended with Odin adopting him.
Loki is a very powerful character who manages to stop the Avengers all together, even in the movie version of the Avengers, Loki manages to trick them all.
Odin is supposed to be eaten by Fenrir in the myth, the Son of Loki. In the movie, Odin is killed by Loki who replaces him and takes the throne from Thor without his knowledge.
Girls love Tom Hiddleston who is a great actor and a good looking one with a bad-boy personality. It is one of the reasons why he has gained so much popularity along with his characters.