Their first appearance was in Episode 16: Attack of the Burger Brigade! The first appearance were only 5 of them (with Well-Done (Black One) not being there. The 5 were under a spell of Rose Marinade, thus enforcing and representing the Glutton's rulership among people and cities. Even physical fighting (with Chase's and Pie Tin's Foodons) would be necessary to enforce the Glutton's law.