Hyper Eggrobo is a giant robot with no legs. It is mostly gray with red circles. It also fires spheres. It has black hands, blue eyes and circles, and six little claws under it. If the player looks closely, Gemerl's head is located on Hyper Eggrobo's head.
Hyper Eggrobo will attack by slamming its hands on the ground, punching his opponent, grabbing the player and slamming them on the ground and bouncing three balls off of his hands. The robot's weakness is its head and in order to get up there, the player can jump on its hands as they move up after smashing the ground, or jumping on the balls until they reach the head. A quick way of defeating Hyper Eggrobo is using Cream the Rabbit's Tag Action and using Cheese to attack Hyper Eggrobo. After eight hits (six in easy mode), Eggman will escape with a damaged Gemerl and the game will end there unless the player has all seven of the Chaos Emeralds and the leading character is Sonic, in which the Nonaggression follows after this fight.
This is the only second-to-last boss in the Sonic Advance series not to have the name "Super Eggrobo," although it is likely an evolution of it.
It is also breaks the pattern of the past two versions being fought in stages named X-Zone and XX