In the comics, Adam Warlock was an artificial human named Him created by an organization called The Enclave to be the “perfect human.”
Warlock was the one who lead Earth’s heroes in the battle against Thanos in The Infinity Gauntlet, but years later, he obtained the Infinity Gauntlet and was temporarily split into two beings, the evil half being called The Magus.
Outside of the comics, he’s appeared in The Avengers: Earth’s Mightiest Heroes and the Guardians of the Galaxy animated series, the latte of which is in a separate continuity from the movies.
There was also a cocoon seen in the first Guardians of the Galaxy movie at The Collector’s museum that looked a lot like the one that belonged to Warlock in the comics.