Waluigi

Waluigi is a character found in the Mario series who was made to rival Luigi. Waluigi mainly only appeared in spinoff games such as Mario Tennis and Mario Party 3. Waluigi is known to be Wario's partner ever since Waluigi made his first appearance in Mario Tennis for the Nintendo 64 and was voiced by Charles Martinet ever since. He is also possibly Wario's brother, due to their similar appearance and the fact that their rivals, Mario and Luigi are brothers. Waluigi also appeared along with Wario and Luigi in Super Mario Advance games as a palette swap of Mario.

Waluigi's hat has an upside down L on it, showing his rivalry with Luigi, similar to Wario who has a W on his cap, shown to be an upside down M. Waluigi wears black overalls and purple clothes.

Appearances
Waluigi's first appearance was in the Mario Tennis for the Game Boy Color and Nintendo 64, as Wario's doubles partner. Later, along with Princess Daisy, he joined the Mario Party series' roster in Mario Party 3 where he played an antagonistic role, in which he owned an island full of traps; he has been a playable character in many entries in the series since, as well as various Mario sports and kart. He and Wario were also the main characters of the intro movies to Mario Golf: Toadstool Tour and Mario Power Tennis. He acts as an antagonist in Dance Dance Revolution: Mario Mix, in which he wreaks havoc in the Mushroom Kingdom by stealing special objects called the Music Keys in order to hypnotize the world with his dancing, thus enabling him to conquer it.

Mario Kart series
Waluigi has appeared in Mario Kart: Double Dash!!, Mario Kart DS, and Mario Kart Wii. It has been confirmed that he will not appear in the upcoming Mario Kart 7.

Mario Kart: Double Dash!!
Waluigi is one of the characters in Mario Kart: Double Dash!! The anti-version of Luigi, Waluigi is a Middleweight Class Character, have Bob-ombs as his Special Item, along with Waluigi Stadium being his course, and Waluigi Racer noticeably being his kart.

Staff Ghost Courses in Mario Kart Wii

 * Waluigi Stadium

Game Appearances

 * Mario Tennis series *GBC is only GB/GBC appearance
 * Mario Kart series (After Double Dash!!) *7 is appeared background in Waluigi Pinball.
 * Mario Party series (After 3, except Advance)
 * Mario Golf series (After Toadstool Tour)
 * Game & Watch Gallery 4
 * Mario Football series
 * Mario Baseball series
 * Mario Hoops 3-on-3
 * Mario Sports Mix
 * Dance Dance Revolution: Mario Mix
 * Yakuman DS
 * Itadaki Street DS
 * Fortune Street
 * Super Smash Bros. Brawl (as a trophy)
 * Mario & Sonic at the Olympic Games
 * Mario & Sonic at the Olympic Winter Games
 * Mario & Sonic at the London 2012 Olympic Games

Trivia

 * Mario Kart 7 is the only game where Waluigi Pinball was a stage, but Waluigi himself didn't.