Loki Laufeyson (Earth-6531)

"Such bluster. How very typical. Ever the sheltered son. So many fractured delusions. You know nothing of war. For all these countless millennia, when it comes to the two of us, you seem to have avoided the simplest of conclusions. Instead, you feel the incessant need to avenge every wrong you perceive from your position of languid morality...as if it were some sort of game. Quite sad. But if it's a war you truly desire, Thor, then I can happily provide it."

- - Loki to Thor

Loki was the infamous son of Laufey of Jotunheim, who was abandoned and left to die by his father during his birth, but who was took over by Odin, who adopted Loki as his son both out of love and in the hopes of achieving peace between Jotunheim and Asgard. For years he was raised as the son of Frigga and younger brother of Thor, becoming known to ancient humans as the God of Mischief. As time waged on, Loki became obsessed with the idea of becoming the King of Asgard, and eventually, after learning of his parentage, plotted a takeover of the world and the banishment of Thor to Midgard, growing to become his brother's greatest nemesis and later ally.

Early Life
Laufey was born as the only son of Laufey on the frozen Jotunheim, and was soon abandoned by his father in a temple because of his small stature, perceived as a deadly weakness in Frost Giant culture. During the Battle of Jotunheim,Odin found the baby Loki, taking him as his own son. With use of magic, Odin was able to disguise Loki's Jotun traits so he would look like a normal Asgardian, and was then raised as the son of Frigga and younger brother of Thor.

The Asgardian Prince
Loki and Thor developed a deep bond and friendship. While Thor took his father's traits of strength, arrogance, and stubbornness, Loki developed his mother's artistic sensibilities and sorcery, which he always practiced with her in the Asgardian Palace. Thor always took Loki to live "adventures", and doing pranks around Asgard. Together, they met Sif, Fandral, Volstagg and Hogun, becoming their best friends even to adulthood.