"I'm a Wario, I'm a gonna ween!"
Wario is the main character and hero of the Wario Series. His archrival is Mario, and his best friend/brother is Waluigi. Despite having no friends in Wario Land or Mario Brothers, he has many of them in Wario Ware, where he is depicted as a gross, biker who is greedy and the boss of Wario Ware.
After the success of Mario Land 1, Nintendo decided to make a sequel. They thought of making Tatanga return, or have Bowser as the bad guy. One employee, Totaka, the voice of Yoshi, suggested that Mario should have a rival. They took the Japanese phrase "Wa", meaning "Bad" and combined it with Mario, creating Wario, or "Bad Mario".
Wario was extremely popular following the release of Mario Land 2. Hudson Soft, the creator of Bomberman, wanted Nintendo to make a game combining their flagship character Bomberman with the at the time popular villain Wario, making Wario Blast Featuring Bomberman, a game where Wario and Hudson's Flagship went toe to toe in a bomb battle.
Following the popularity of Wario and the recent partnership with Camelot and Nintendo to make Mario Tennis and Mario Golf games, Nintendo decided that during the development of Mario Tennis 64, that Wario needed a new partner due to the fact that his old partner, Bowser, was partnered with a Boo. So Nintendo decided to do the same trick they did with Wario, taking "Wa" and combining it with Luigi's name to create, "Waluigi" , Wario's mysterious partner/brother.
Wario Land Edit
Wario Land is Wario's adventure platformer series. He owns a Castle on Kitchen Island, and goes on adventures either to get treasure or to defeat a foe. He grew a nemesis/rivalry with Captain Syrup, who ransacked his castle twice and aided him in Wario Land Shake It, only to backstab him in the end.
Wario has also many moves he can do, like a Dash Attack or Shaking foes.
Wario was featured in Brawl and Wii U/3ds as a playable character who represented the Wario series, mainly getting his moves from Wario Ware.
Wario also appeared in Wario Ware, where he was a micro game maker. He had many friends, including Jimmy T and Mona.