Saturday morning cartoon that ran from 1979-1984. It aired on ABC during "The Plastic Man Comedy/Adventure Show." Peter Cullen provided the voice for both Mighty Man, while Frank Welker was the voice of Yukk.
Mighty Man was really millionaire Brandon Brewster, but when he hit himself with his -- umm -- Mighty Man Ray, he'd shrink to less than a foot tall and gain super-strength and the ability to fly.
Yukk was Mighty Man's dog. He walked around on his back legs and wore a little doghouse over his head because he was the ugliest dog in the world. Anytime he took off his doghouse, sirens and screams would be heard, and anyone within eyeshot would be severely traumatized by the experience. He was so ugly, he could even destroy inanimate objects. That's really damn ugly!
Their battle cry was: "MIIIIGHTYYY MAAAAN! And Yukk." or occasionally "YUUUUKK! And Mighty Man."