Mac Gargan

Mac Gargan is usually the Marvel super-villain known as The Scorpion. However, for several years, he was instead known as Venom, and, for a brief time, was even known as Spider-Man, as a part of Norman Osborne's Dark Avengers

Earth's Mightiest
Gargan, as the Sinister Spider-Man, defeated Iron Man in the first round, but was defeated by the Black Knight in round 2.

Goin' Green
Gargan, as the Scorpion, vs Piccolo in the first round.