Annihilus is a powerful being from the Negative Zone.
At some point, Leader supplied Annihilus with mind-control technology and took control of Skaar. He appeared in Vista Verde in order to take enough gamma energy to invade the Earth. He sent Skaar to Earth so that he would be defeated and captured. Skaar then escaped with a gamma weapon using it to open the portal.
While his minions attacked the group, Annihilus fought Hulk. Hulk defeated Annihilus and rendered him powerless.
Annihilus was voiced by Robin Atkin Downes.