Egghead

Elihas Starr, a.k.a Egghead, is a former Pym Tech scientist who was fired by Hank Pym for accidentally causing a chemical explosion that killed fellow employee's, including Eric O'Grady. The explosion deformed Starr, causing him to have his head shaped like an egg. Angry at Pym, he created a life-model decoy of Grady called the Black Ant to get revenge on Pym.