From the Super Mario Wiki
Patrick Pinney (nickname: Pat Pinney) is an American actor and voice actor who played King Koopa in King Koopa's Kool Kartoons. He currently resides in Mobile, Alabama. Patrick Pinney took over the role after Christopher Collins left the show in 1990. Since he was primarily a voice actor, this role was one of his few live acting roles. Currently, he plays Painty the Pirate on SpongeBob SquarePants.