Doctor Eggman

Doctor Eggman is the primary antagonist from the Sonic the Hedgehog series. He is an obese scientist with an IQ of 300 who wants to dominate the world and create his Eggman Empire, but his plots are thwarted by Sonic the Hedgehog and his friends. He is one of the Sonic the Hedgehog characters present in Archie Comics' crossover Worlds Collide.

Story
Note: This article only covers his appearance in Archie Comics' Sonic the Hedgehog and Sonic Universe comic book series.

Background
Doctor Ivo "Eggman" Robotnik (born Julian Kintobor, later known as Dr. Ivo Robotnik; also known as Robo-Robotnik v2.0, Robotnik Mach II and Eggman) is a version of Dr. Ivo Robotnik from an alternate timeline of Archie Comics' Sonic the Hedgehog comic series. In his native universe he was defeated by the Freedom Fighters after he roboticized himself, only to survive by uploading his digital consciousness to an unfinished space station he had constructed. He languished there for years, facing eventual shutdown, until a chance encounter with Dr. Ivo Robotnik of Mobius Prime who had been inadvertently teleported to Robo-Robotnik's future reality by E.V.E.. This meeting inspired Robo-Robotnik to continue fighting and eventually managed to rebuild his body—then bombarded Mobius with atomic weapons, killing his nemesis King Sonic and the entire Royal Family. With no one left to fight, and having discovered that the Robotnik of Mobius Prime had been killed, he traveled to Mobius Prime to "fill the void" in both his life and that world's Sonic, and became known as Dr. Eggman once his original robotic body was destroyed.

Eggman eventually was de-roboticized by the Bem, becoming a flesh and bone Overlander once more, but continued to act as the primary antagonist in the Mobius Prime reality. After suffering numerous setbacks to his conquest, Dr. Eggman's mental stability declined until he finally succumbed to complete madness following a major defeat by Sonic, and was subsequently locked away by Snively, only to escape and be taken into custody by his enemies. During the Iron Dominion's takeover, Eggman regained a semblance of his sanity and finally escaped from New Mobotropolis's prison after the fall of the Iron Queen. He returned to the Eggdome with Snively and the local Dark Egg Legion chapter to plan for his renewed battle with Sonic. This led to the launch of the Death Egg Mark 2, Operations Clean Sweep, Titan, Deadly Cuddles and the use of the Egg Annihilator Beam, all to destroy New Mobotropolis. All these attacks were stopped, but Eggman won the roboticized Sally to serve him.

Sonic Universe #50
Dr. Eggman orders Metal Sonic to head to the interdimensional portal to meet his new partner Bass (Whom Eggman describes as a Base villain).

Sonic the Hedgehog #247/FCBD 2013
Dr. Eggman sets up the Genesis Wave before entering the interdimensional portal, hoping that Dr. Wily (referring to him as Albert) is ready.

Mega Man #23
Dr. Wily pushes Break Man into pursuing Mega Man so that he and Dr. Eggman's (referring to him as Ivo) plan can go uninterrupted, and later enters an interdimensional portal.

Worlds Collide
Dr. Eggman and Dr. Wily first made contact with each other when Wily's examination of the blue Chaos Emerald caused a connection between their dimensions. Realizing the simularities of their situations, they began to work together, creating the Skull Egg Zone and the Wily Egg as a base of operations. Their next step was unleashing the Genesis Wave on both worlds, enabling them to kidnap Sonic's friends to make the Roboticized Masters to acquire the remaining emeralds. After Mega Man and Sonic teamed up, they began to construct the Egg-Wily Machine X as a counter-measure. Eggman later decided to abandon Wily and steal the Wily Egg when push came to shove (with Wily having mutual feelings regarding Eggman on the matter, albeit in reverse), although he promised that he would carve Wily's face into a continent in remembrance of him. Eggman later tried to kill Dr. Light when he realized he had leaked to Rouge information relating to the Wily Egg, as well as his trying to contact the heroes by throwing him out of the Wily Egg. However, this soured his friendship with Wily beyond repair.

In the end, he sabotages Super Sonic's attempt to restore their world, causing them to return to an altered version of their home.

Aftermath
Dr. Eggman, along with Orbot and Cubot end up in the Efrika Plains along with the remains of the Egg-Wily Machine X. Eggman, annoyed by his recent failure blames Al for everything.

They, along with Sonic, Blaze the Cat and later Tails are the only ones who recalls Worlds Collide. (Sonic the Hedgehog #252 & Sonic Universe #55)

Incidentally, while Dr. Wily's memory of the event & his former parter is gone, though he has some recollection in the form of an unexplained violent urge to stomp on a carton of eggs. (Mega Man #28)

Although not in the Mega Man comics themselves, one of Roll's costumes, as part of the 31 days to Halloween by Archie Comics artist Ryan Jampon, depicted Roll wearing Dr. Eggman's outfit as a potential trick-or-treating outfit.

As a result of his interference with Sonic's attempt at undoing the Super Genesis Wave, their planet ended up cracked apart, and also resulted in the creation of the Genesis Portals, with Eggman learning this after overhearing Silver tell Sonic about them after sending an Ifrit through a portal.

Trivia

 * Dr. Eggman's Japanese voice actor was Chikao Ohtsuka, who voiced Dr. Weil in the Mega Man Zero series. Coincidentially, both Eggman and Weil had an ultimate creation known as Omega (E-123 Omega for Eggman, and Omega for Weil).
 * Coincidentally, Dr. Eggman in the beginning of Sonic Unleashed managed to pull a similar stunt on Sonic that Dr. Wily frequently pulled whenever he was defeated.