Fario

Fario is Mario's long lost brother who had got rescued by Mario in Donkey Kong 4.

Apperance
Fario wears purple overalls and green shoes, everything else is the same to Mario.

Donkey Kong 4
Fario is the person Mario had to rescue in Donkey Kong 4, he was kidnapped by Donkey Kong.

Super Mario: Smash Generation
Fario is an unlockable character in Super Mario: Smash Generations. He is unlocked by completing 50 levels in story mode.

Super Mario 4D
Fario is an unlockable character in Super Mario 4D. He is unlocked by completing World Propeller.

Donkey Kong Deluxe
Mario has to rescue Fario in level 9 in order to unlock him.