He is usually portrayed as a selfish and greedy treasure hunter who, in karmic irony, routinely loses his spoils by adventure’s end.

The character Foreman Spike, a possible inspiration for Wario, first appeared in the 1985 game Wrecking Crew.

[15] Wario's first named appearance occurred in the 1992 game Super Mario Land 2: 6 Golden Coins.

He wears a plumber outfit with a yellow-and-purple color scheme, which is a short-sleeved yellow shirt, purple overalls, and a blue "W" on his hat.

[21] When asked whether Wario was a brother to Waluigi in 2008, voice actor Charles Martinet stated that while he did not know, he felt that they were just "two nice, evil guys who found each other".

[22] Nintendo originally considered making Wario a German character before he developed into an Italian like Mario.

During his audition for the part, Martinet was told to speak in a mean-and gruff-sounding tone; he said voicing Wario is a looser task than voicing Mario, whose speaking manner and personality are freer-flowing, rising from the ground and floating into the air, while jealousy is one of Wario's characteristics.

[26][27] Etsunobu Ebisu and Takahiro Harada, producers of Shake It!, considered Wario to be a reckless character who uses his strength to overwhelm others.

Because of this, Tsukawaki wanted Wario to act macho rather than silly and asked the art designers to emphasize his masculinity.

[29] During an interview with Kikizo, video game designer Yoshio Sakamoto, who was a member of R&D1 since its early days, stated the project centered around Wario because the team "couldn't think of anyone else best for the role",[30] and he was then described as "unintelligent"[31] and "always idiotic",[30][32] which is the reason he was chosen as the star of the WarioWare series.

[32] According to an early 1990s Nintendo guide, Wario was Mario's childhood friend, which Kotaku later contested in a parody article.

[16] In the WarioWare series, he became as a smelly slob, while in Mario Strikers: Battle League, his super shot special involves smashing his butt into the ball, followed by him devouring a giant clove of garlic.

[35] In WarioWare: Touched!, consuming garlic transforms Wario into "Wario-Man", a superhero with powers relating to garlic-induced flatulence and bad breath.

Wario prominently uses bombs as tools and weapons in the WarioWare series as a visual motif to represent the time limit of a microgame.

[34] In 2000, Wario Land 3 was released for the Game Boy Color; it is another sequel that uses the same mechanics and concepts as its predecessor.

[48] In 2018, the Nintendo 3DS game WarioWare Gold was released, featuring 316 microgames and combining elements from Twisted and Touched.

[64] In a May 2021 episode of Saturday Night Live, host Elon Musk starred as Wario in a sketch in which he was put on trial for murdering Mario in a kart race.

"[73] IGN editor Travis Fahs said that while Wario is not the most likeable character, his strong confidence overshadows his flaws and makes him entertaining.

[74] Audrey Drake of IGN said of Wario, "[A]ll this weird dude seems to care about is amassing as many material possessions and shiny things as possible",[75] KhalidEternalNigh of Destructoid praised the character, describing him as "fat, lazy, greedy, and a cheater" and said: "[D]espite all of this I can't help but love him.

He also said, "Wario trumps Mario as my family mascot, born with a crucial, relatable need to be louder and larger than life.

Sholars concluded, "Wario was conceived out of a desire to put a twist on the familiar, but his creators tapped into a powerful, universal constant: The Unrepentant Asshole.

"[19] Edwin Evans of Eurogamer praised Wario for being "repulsive" and "brilliant" and said, "In general, Wario isn't the star he used to be, [...] [b]ut he remains a crucial component of the Nintendo pantheon, the counterbalancing touch of malevolence and cunning without which Mario's star wouldn't shine quite so brightly.

[81] In Icons of Horror and the Supernatural: An Encyclopedia of Our Worst Nightmares, Volume 1, S. T. Joshi cites Waluigi and Wario as archetypal examples of alter egos.

They mentioned that Wario possesses a unique move in which he uses his teeth to efficiently chomp through anything, including other fighters, explosives, and even his own motorcycle.