The Egg Mars was initially piloted by Decoe and Bocoe to save Eggman after his attempt to deceive Knuckles and obtain one of the Chaos Emeralds failed. He briefly attempted to use the Egg Mars to force the heroes to turn the Emerald over to him, only for Metarex Jumpee to appear to claim the jewel. Despite the Egg Mars' superior size, it proved no match for the Metarex and was destroyed.