Sunday is Monkey Covers day here at YACB. Because there's nothing better than a comic with a monkey on the cover!
An armored gorilla punches some dude in the face on John Byrne's cover to Doomsday + 1 #6 (1976).
(Standard disclaimer about armored gorillas not really being monkeys applies.)
Image courtesy of the GCD. Click on the image for a larger version.