The machine is Robotnik's Egg Mobile attached to a bipedal mech that contains two bouncy Bobbins on the arms, along with spikes on its feet.
Robotnik will walk back and forth across the arena (although not to the end of the screen to the player's safety), occasionally stopping to charge an attack by moving the arms backwards, and thrusting them forward. This is the best opportunity to attack.
Interestingly, the mech can be easily defeated in a mere few seconds by simply running to the end of the screen, waiting until the mech drops in, and attacking from behind.
The color appearance of the boss varies between the Good Future and the Bad Future. In the Bad Future, the mech is a red and drab-gray color, while in the Good Future it appears as a pink and steel-blue-colored machine.
In concept artwork of the game, EGG-HVC-001 has dual pinchers the ends of the arms instead of bobbin's.
This is one of the few bosses in the game to have a different color palette based on the future.
HVC-001 is the model number for the Family Computer (Famicom), which is known as the Nintendo Entertainment System outside of Japan. The name of this boss may have been directed as a jab at Nintendo.