Black Doom

Black Doom is a main antagonist of Shadow the Hedgehog. He is the leader of the Black Arms, a group of aliens who seek to conquer Earth. He is trying to collect the Chaos Emeralds so that the Black Arms can use Chaos Control to teleport their base, the Black Comet, to the Earth's surface, where it will release a toxic gas that paralyzes all living things except those with Black Arms DNA.

History
In the final ending of Shadow the Hedgehog, Black Doom persuades Shadow to give him the Chaos Emeralds. When he does, the Black Comet is teleported down to Earth, and Sonic, Tails and the other supporting characters inside the Black Comet are paralyzed. Shadow opposes the Black Arms, and finds Black Doom. Black Doom tells Shadow that Professor Gerald needed Black Doom's help to create Shadow, but Black Doom asked for the seven Chaos Emeralds in return. Professor Gerald modified the Eclipse Cannon so when the Black Comet returned in fifty years it could be destroyed.