A brief history of Waluigi
(N4G Wii)

Waluigi`s origins were simple. Mario Tennis had a system of partners and rivals. Each character needed a doubles partner. Mario had Luigi, Peach had Daisy, Yoshi had Birdo, and so on. Wario, on the other hand, had no one that really fit his quirky personality. Wario would also be positioned as Marios rival, and since Marios partner was Luigi, he too needed an appropriate rival.