Leader: Ultron-5 (as the Crimson Cowl)
Members: Klaw, Whirlwind, Radioactive Man, Melter, and Black Knight III

The second group of costumed criminals calling themselves the Masters of Evil were organized by the robotic Ultron-5, creation of Henry Pym (then known as Goliath), who concealed his identity from the others in the guise of the Crimson Cowl. Ultron planned to launch a surprise attack on the Avengers in their mansion headquarters, and maneuvered the Avengers' butler Edwin Jarvis to sell them the blueprints to the Avengers' security systems. Their raid was successful and the Masters took the Avengers captive. However, the second Black Knight, who joined the Masters in order to betray them to the Avengers, initiated the Avengers' rescue. The second Masters of Evil were defeated by the Avengers, but Ultron-5 escaped, to plague the Avengers subsequently without human accomplices. Klaw, the Melter, Radioactive Man, and Whirlwind challenged the Avengers a second time, but were easily defeated.

First Appearance: AVENGERS #54