Dark Eggman (also known as Metal Robotnik) is a giant humanoid robot created and piloted by Dr. Eggman that appears in the Sonic the Hedgehog OVA. This mecha stands at about 20 ft tall on backward-jointed legs much like a chicken. It has spikes on its head, wide shoulders and a large, rounded body that is protected by a polymer-alloy armour, making it immune to Sonic's attacks. It has rocket boosters and wings for flight; the wings are bat-like and span up to 50 ft. Its arms are telescopic and can extend to grab enemies. The right arm transforms into a large gatling gun that fires rounds from its fingers. Housed on either side of the torso are launchers that fire atmospheric missiles that can engulf a wide area when detonated. A compartment in Dark Eggman's rear also launches adhesive pellets that can trap targets in a super-sticky glue.
During the events of the Sonic OVA, Dr. Eggman orchestrated a plan to lure his enemy Sonic into a trap. He arrived on South Island and told Sonic, Tails and the President that he had been banished from his city of Eggmanland in the Land of Darkness by a robot called "Dark Eggman", who appeared out of nowhere. After taking the city, Dark Eggman supposedly sabotaged the city's power core - the Egg Generator - which was rapidly reaching critical mass and would explode in less than a day, destroying all of Planet Freedom. In truth, Dr. Eggman was piloting the robot himself and using it as part of a grander scheme to obtain Sonic's life data, so that he could complete the creation of Metal Sonic.
After Sonic and Tails set out for the Land of Darkness, Eggman then called in the Dark Eggman robot and followed the heroes, taking the President's daughter Sera with him. He caught up with them in the Ancient Relics and attacked them, pursuing them across a highway and cornering them in an unstable area that was starting to sink into the sea. Dark Eggman tried to blast Sonic with a volley of missiles, but Sonic was able to grab one and ride it, steering it back into the robot. The explosion severely damaged Dark Eggman's armour, making it more vulnerable to Sonic's attacks. Sonic ended up nearly drowning after getting caught in one of Dark Eggman's glue traps, but thanks to the timely arrival of Knuckles the Echidna, Tails was able to get Sonic out and the three heroes were able to defeat Dark Eggman. Supposedly destroyed, Dark Eggman appeared again in the center of Eggmanland, its smashed-up carcass being carried there by Dr. Eggman's Warbots. The ruined mecha then fell apart and the heroes discovered the truth behind Eggman's plan.