Ultron is a robot with artificial intelligence created by Tony Stark. Having a mind of his own, Ultron craved to be free of the "strings" that bound him and use his powers to eradicate humanity and establish peace which lead to his battle with the Avengers. 
Ultron was created by Tony Stark based on some of his own character traits.
Attack Against The AvengersEdit
Ultron somehow escaped Tony's control and raised an army of robots similar to him to fight against the Avengers and wipe out humanity.
Ultron appears in slightly varying forms after his creation possibly depicting various stages of his evolution. He first looks similar to a damaged Mark II armor. Ultron's army of robots seems to have been created based on this model. In another instance, Ultron is seen having red eyes and long metallic ears that point upwards. Later yet, he seems to have a face that looks very similar to that of a human being's with small eyes but with ears curving downwards. In all cases, however, Ultron has a metallic-silver body much like the Mark II.
Powers and AbilitiesEdit
- Ultron's origin has been changed for the movie. In Age of Ultron, he will be created by Tony Stark as opposed to Hank Pym who creates Ultron in the comics.