Iron Man, Vol. 1 #64 (1973)

Rokk Cometh
After making his upgrades, Tony occupies his time by helping to demolish and rebuild some run down buildings in Detroit. During this, he is attacked by Dr. Spectrum, this time doing well enough in battle to make Spectrum flee. After returning to the S.I. offices and confronting Happy, he is interrupted by Dr. Obatu. Obatu asks for Iron Man's protection, and is then attacked by Rokk, a large, powerful creature. Happy gets Pepper to safety, and Rokk's departure with a captive Obatu gives Stark the opportunity to don his armour once more. He pursues Rokk, and is nearly defeated by him before Rokk disappears. It is then revealed that Rokk was a creation of Dr. Spectrum, who then plans to finish Iron Man off for good.
Release Date: 1973