Flame Chomp Coin
From the Super Mario Wiki
A Flame Chomp Coin is an item in Puzzle & Dragons: Super Mario Bros. Edition that allows the player to transform certain types of enemies into stronger forms. Flame Chomp Coins can be obtained by defeating Flame Chomp-type enemies or by winning them in the Lucky ? Blocks game in Toad Houses.
Transforming enemies into stronger forms require a certain amount of Flame Chomp Coins. Transforming Chain Chomps into the enemy "Chain Chomp & Flame Chomp" requires three Flame Chomp Coins, and can be upgraded even further to the enemy "Chain Chomp & Flame Chomps" for six more. Wigglers can also transform with Flame Chomp Coins into the enemy "Wiggler & Flame Chomp" with three Flame Chomps Coins.