After Wadaisy killed Wamario, Wabowser, and Wawaluigi, she stuffed their bodies inside the Washing machine that is convenientently located that fuses/kills people. This fused them into Wabowarigi. Wabowarigi fought Daisy, but he was defeated and fled. Later, in Super Waluigi World, Wabowarigi was the boss in Pipe Land. He was defeated and fled to parts unknown. He also starred in his own shame, which was called Wabowarigi Unite!
In The Super Wario Bros. Strike Back!, Wabowarigi first appeared in the episode Wabowarigi Attacks! He is accidentally created by Some tiny moron that nobody cares about, who throws a Dry Bones head into the Wa-Machine as it powers up. Since the Wa-Machine had already contained Wabowser, Wamario, and Wawaluigi, the mess of Wa-guys and Dry Bones' heads combined into one monstrous creature. He attacked Wario, Waluigi, and the last remnants of the Koopa Mafia before he was finally brought down by his reverse-clone, Bowarigi.
Wabowarigi has the ability to shoot out fire from his mouth, whack people with his tennis racket and, only in The Super Wario Bros. Strike Back!, control two floating Dry Bones' heads and throw them at people.