Flame Chomp did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
Flame Chomps (also called Fire Chomps) are airborne Chain Chomps that have fireballs for tails. They first appear in Super Mario Bros. 3, normally in sky levels. They fly around Mario, attempting to hit him with the Fireballs that make up its tail by spitting them at the plumber. If all of its fireballs are used up, it will begin flying around Mario faster while flashing, exploding afterward. Unlike Chain Chomps however, Flame Chomps can be defeated with most attacks, including jumps and Fireballs from Fire Mario.
Flame Chomps are enemies in Super Mario Maker Chi and are introduced for the first time in the series along with four new sub species. Freeze Chomps fire iceballs that freeze Mario, Superball Chomps fire off Superballs, Dirt Chomps shoot rolling dirt balls, and Volt Chomps fire direct bolt projectiles.