Doomsday Project

The Doomsday Project is a gigantic, factory-like tower that is the mad Dr. Robotnik's creation and it served as the power-hungry genius' ultimate plan to complete his scheme of transforming Mobius into a lifeless wasteland, and it is featured in the titular final episode "The Doomsday Project" of the second season of the cartoon series Sonic the Hedgehog (also known as Sonic SatAM).

Description
Deployed in the form of pods, the Doomsday Project unleashes devastating energy beams. Each pod is virtually indestructible, able to endure even explosions at point blank range.

The Doomsday Project's prototype model was first deployed against the Wolf Pack. Sonic the Hedgehog, Sally and Antoine Depardieu joined their canine allies in disabling the pod, though they were nearly defeated and captured by Snively.

As part of his final plan for the Project, Robotnik erected an enormous tower to deploy thousands of pods across Mobius by opening subterranean tunnels. Combining forces, all the Freedom Fighters launched an assault on the tower. However, they proved unable to destroy the machine until Sonic and Sally utilized the energies of the Deep Power Stones. The tower was then destroyed, seemingly taking Dr. Robotnik with it (although 2 ships were seen escaping, one could have been the Freedom Fighters and the other implied to be Robotnik's ship).

After this, Snively's pod which he used to survive opens up, revealing the villain, now dressed in a purple cape and black gloves. Pleased that his uncle finally let Sonic defeat him, Snively plans to take Robotnik's place. The worst part is that he is not alone.

Trivia

 * It is also called the "Doomsday Machine", considering its destructive capabilities as a doomsday device.
 * Doomsday Machine is also the name of an intergalactic flying ship from the Star Trek franchise.
 * It shares similarities with the Ultimate Annihilator from the Sonic the Hedgehog comic book series.