Fire Mario is an ability in the Mario series. When Mario, Luigi, Peach, a Toad, or Rosalina grabs a Fire Flower, he/she gains the ability to hurl fireballs and throw them infinately until he/she gets injured. When he/she finds this Power-up, his/her clothes have warmer colors. It's polar opposite is the Ice Flower, which turns characters into Ice Mario.
He was first able to do this in as early as 1985 in the game Super Mario Bros. for the Nintendo Entertainment System. Other appearances include Super Mario Bros. 3, Super Mario World, New Super Mario Bros., Super Mario Galaxy, and Super Smash Bros. Brawl.
In The Super Mario Bros. Super Show, this outfit is referred to as Super Mario regardless of whether Mario can throw fireballs.