From the Super Mario Wiki
“Honestly, a dog could be a better servant!”
King Windbag was featured prominently in The Adventures of Super Mario Bros. 3 episode "Life's Ruff". Princess Toadstool had come increasingly concerned over King Windbag's bullying attitude and had sent Luigi to sort things out with him.
Shortly after arriving at King Windbag's castle, Luigi and King Windbag were attacked by Hip and Hop Koopa, who stole King Windbag's magic scepter. Hip and Hop then proceeded to transform Luigi and King Windbag into dogs.
King Windbag and Luigi attempted to give chase to Hip and Hop and ended-up chasing them through a Warp Pipe to Miami, Florida. As Luigi was chasing down Hip and Hop through a dinner party, King Windbag was captured by a dog catcher named Herman, who later captured Luigi.
While in the dog-pound, King Windbag is forced by Luigi to cooperate with several dogs to escape the pound. Succeeding in their escape, King Windbag and Luigi manage to track-down Hip and Hop to the Kennedy Space Center, and, after some trouble with Herman, manage to capture the Koopaling twins.
King Windbag manages to reclaim his scepter and, after returning himself, Luigi, Hip and Hop back to Mushroom World, "turns over a new leaf" and decides to become a kind king and stop bullying his servants.