Sonic apocalyptic monster

In the newer Sonic games the final boses are rarely Doctor Eggman but instead a massive monster with tremendous power. They require super characters to take them down (Super Sonic)

The monsters include in order of appearance:

Chaos- In Sonic Adventure The water beast called Chaos used the 7 Chaos Emeralds to become a god of pure destruction and power called Perfect Chaos.

Biolizard- In Sonic Adventure 2 The Biolizard who was the prototype of the ultimate lifeform used the 7 Chaos Emeralds for Chaos Control to merge with Space Colony ARK and become The FinalHazard.

Metal Sonic- In Sonic Heroes Metal Sonic extacted bio data from Sonic, Shadow the Hedgehog and Chaos to transform into a dragon like monster called Metal Madness. He then sprouted wings and became Metal Overlord.

Black Doom- In Shadow the Hedgehog Black Doom was the leader and oldest of an alien army called The Black Arms. He is the only villain to transform without Chaos power making his form an ultimate form rather than a super form. His form is called Devil Doom, he is mutated beyond belief and is the most powerful apocalyptic monster in the universe

(Unknown)- In Sonic the Hedgehog (2006)]] there is confirmed to be another massive beast which could be Iblis because of Sonic being the Iblis Trigger.