Fire Guys are Shy Guys that have the power to use fire when needed. They have a blue mask, instead of white like the usual Shy Guy. They also have a grey belt strap and a black belt buckle. They usually live in warmer climates such as volcanoes.
Mario Kart: All-Star Circuit
In the game Mario Kart: All-Star Circuit, they open toll booths in Volcano Raceway in the Star Circuit.
Super Mario Returns: Attack of the Shy Guys
In certain levels like volcanic levels, Multi Guy transforms into Fire Guy.