Death Egg II

The Death Egg II is Dr. Eggman's base in Sonic the Fighters.

Description
Quite dissimilar in design to the original Death Egg deployed in Sonic 2, this battle station has six colorful subsidiary globes connected to the central sphere, as well as an assortment of arm-like apparatus attached.

Sonic the Fighters
In order to decide who will pilot Tails' single-seater rocket (the Lunar Fox) up to the Death Egg II, the heroes hold a fighting competition, which gives the first eight levels of Sonic the Fighters. The player character then blasts up to the space fortress, where the two final battle arenas are set: When Eggman is defeated, the Lunar Fox departs, and the Death Egg II is shown exploding into tiny pieces.
 * Death Egg's Eye, where Metal Sonic is fought.
 * Death Egg's Hangar, where Dr. Eggman attacks in his Mech even while the countdown to explosion gets into its last 15 seconds.

Sonic the Hedgehog: Episode II
The Death Egg II returns in Sonic the Hedgehog: Episode II. Unlike Sonic the Fighters, the Death Egg II Zone was the eighth and final stage. After jumping in the Lunar Fox, Sonic makes his way inside the battle station and battles Metal Sonic and then Robotnik himself in his Mech. When Eggman is defeated, the Lunar Fox departs, and the Death Egg II is shown exploding into tiny pieces.

Trivia

 * Death Egg II resembles Dr. Eggman's Incredible Interstellar Amusement Park.
 * Oddly enough, the battle with Dr. Eggman is a bonus round.