Wario

One of Mario's most frequently appearing rivals. Wario is an overweight, crude, and greedy man who loves garlic and money. He is often seen alongside Waluigi, although the nature of their relationship is unknown.

Wario's first game appearance was in the Game Boy title Super Mario Land 2: 6 Golden Coins as the main antagonist and final boss. Here, he took over Mario's castle, but fled once the hero defeated him.

Since then, Wario has had antagonistic roles in other games and has also appeared as an anti-hero. He also has his own spin-off franchise, which started with Wario Land: Super Mario Land 3 and has since expanded into other platform games as well as the party series WarioWare.

Wario continues to appear frequently in Mario spin-offs as a playable character, usually classified as a powerful heavyweight.

(Source: Super Mario Wiki)