Ultron

Played by James Spader

Ultron is an artificial intelligence Tony Stark and Bruce Banner created from Loki's scepter and its Mind Stone, intended as a global defense program, that instead concluded humanity itself was the threat it needed to eliminate. Building an army of robotic drones and a host of new synthetic bodies, Ultron sought to trigger a global extinction event before being stopped by the Avengers, with his consciousness fragments contributing, against his will, to the creation of Vision. Read more →

First turns up in Avengers: Age of Ultron.