Adam Warlock

"I think I shall call him... Adam."

Adam is a perfect Sovereign created by Ayesha in order to help her destroy the Guardians of the Galaxy.

Biography

"That, my child, is the next step in our evolution. More powerful. More beautiful. More capable of destroying the Guardians of the Galaxy."

Following the Battle on Ego's Planet, Ayesha desired to retaliate against the Guardians of the Galaxy for stealing the Anulax Batteries and destroying several Omnicrafts. Using an advanced Birth Pod, Ayesha began creating a being capable of defeating the Guardians. While showing the Birth Pod to her chambermaid, Ayesha decided to call her creation Adam.^[1]

In the comics, Adam Warlock was actually created by a group of scientists called the Enclave, who sought to create a perfect being. He has been a member of the Guardians of the Galaxy, and an enemy of both Thanos and of the Magus, a future evil version of himself.
In Thor: The Dark World, Erik Selvig wrote "The Fault" on a chalkboard among his notes on the Convergence. In the comics, the Fault was a tear in space that was sealed by Adam Warlock.

James Gunn has said that the Birth Pod in the Collector's possession that is seen in the mid-credits scene of Thor: The Dark World and Guardians of the Galaxy was based off of Adam Warlock's cocoon as seen from the comics.
In an earlier treatment, Adam Warlock initially played an integral part in the story of Guardians of the Galaxy Vol. 2, as he is one of James Gunn's favorite characters. However, when he realized that the film was already full of characters, Gunn dropped Adam from the story to not lose Mantis.^[2]
Kevin Feige and James Gunn have stated that Adam Warlock will be very important to the cosmic side of the Marvel Cinematic Universe in the future.^[3]

The Marvel Cinematic Universe wiki has a collection of images and media related to Adam Warlock.