Waluigi (Japanese: ワルイージ, Waruīji) is Luigi's very tall and skinny rival, and Wario's partner. Waluigi made his debut in Mario Tennis, and since then, he has made playable appearances exclusively in Mario franchise's spin-off titles. He has been voiced by Charles Martinet ever since his debut. His name is a portmanteau of the Japanese words, Warui and Ruīji, meaning "bad" and "Luigi". In addition, his name is an anagram to the Japanese word Ijiwaru, which can mean "ill-tempered" or "cruel". The details of Waluigi's past are unclear since he has no confirmed background, although he has evidently been antagonizing the Mario Bros., especially Luigi, for quite some time before his debut as seen in the opening of Mario Tennis, where he and Luigi confront each other. He has a particularly strong rivalry with Luigi, who he constantly harasses, but he apparently has animosity toward most others in the Mushroom Kingdom, except for his partner, Wario.