Sonic the Hedgehog 2
The Death Egg was introduced in Sonic 2 and served as the final stage of the game. Eggman had it constructed by abducting the animal denizens of Westside Island and turning them into Badniks and putting them to work on the station. Eggman had intended to power the fortress with the Chaos Emeralds, but Sonic collected them before he could. After defeating Eggman on his Wing Fortress, Sonic hitched a ride on the doctor's Egg Jet and pursued him to the Death Egg. There, he fought the Silver Sonic and Eggman himself in his Death Egg Robot. Once Sonic defeated the mecha, the Death Egg seemed to suffer some kind of system failure and began to explode. Sonic got off the station before being engulfed in the flames.
Sonic 3 & Knuckles
The Death Egg was not completely destroyed and had crash-landed on the airborne Angel Island, home of Knuckles the Echidna. Eggman set about building a Launch Base to repair the Death Egg and get it active again and tricked Knuckles into thinking that Sonic the Hedgehog was a villain who wanted to steal the Master Emerald that kept the island floating in the sky. Eggman almost managed a relaunch of the Death Egg, but was interrupted by Sonic and fought the hero using his Big Arm machine. The doctor was defeated again and the Death Egg crash-landed atop Angel Island's volcano. Eggman once again managed to repair the fortress and managed to keep Knuckles and Sonic distracted long enough to steal the Master Emerald, which would provide the Death Egg with an everlasting power source. The Death Egg was launched and released a squadron of Eggrobos to attack Sonic and Knuckles on the Sky Sanctuary. Sonic battled his way through the Badniks and boarded the Death Egg, where he proceeded to cause significant damage. After destroying the Great Eggman Robo, the Death Egg was doomed and both Sonic and Eggman made their escape before it exploded.
The Death Egg has been crewed by various Badniks which are listed below:-