Abomination

Abomination (real name Emil Blonski) was a soldier turned monstrosity by gamma radiation, and is the evil counterpart of Hulk.

The Avengers: Earth's Mightiest Heroes
Abomination was one of the inmates in the Cube. When a breakout happened, he and Absorbing Man helped the Leader to take the Cube.

When the Leader activated his Gamma dome in Las Vegas, Abomination used one of the Leader's Gamma devices to become even bigger and stronger, and faced Hulk. He was still defeated, but was found by Baron Zemo who recruited him as the last member of the original Masters of Evil.