Doctor Eggman (Classic Sonic's world)

Dr. Ivo Robotnik (ドクター・ロボトニック), also known as Dr. Eggman (ドクター・エッグマン) and Classic Eggman (クラシックエッグマン), is an antagonist that appears in the Sonic the Hedgehog series. He is a human and Dr. Eggman's counterpart from another dimension set in the recent past.

Basically a past version of his mainstream counterpart from his younger days, Eggman first appeared during the Time Eater incident where he teamed up with his counterpart to rewrite history in his favor, only to be stopped by Classic Sonic and Modern Sonic. Since then, Eggman has continued to follow his ambitions of creating Eggman Land.

Appearance
Dr. Eggman is depicted as being rotund in appearance, with black pants and leggings, white gloves, a bald head, pince-nez glasses with blue lenses, a bright red nose, and a very bushy auburn moustache. He also wears a red shirt with an oversized yellow collar and gray buckles on his pants.

Past
Dr. Eggman's early history was most likely largely the same as his mainstream counterpart's up until at least some time after the West Side Island incident.

Sonic Generations
In Sonic Generations, during the timeframe of the West Side Island incident, Eggman encountered Sonic the Hedgehog onboard the Death Egg. Eggman proceeded to fight Sonic in his Death Egg Robot, but was defeated. In the aftermath, Eggman got kidnapped by the Time Eater. As it turned however, the Time Eater was controlled by Modern Eggman, Eggman's future counterpart from another dimension, who needed Eggman's help perfecting the Time Eater, which had the power to let both Eggmans undo their previous defeats at the hands of their worlds' native Sonic by erasing the Sonics' actions from history altogether so they would be victorious in the present. More than happy to help his counterpart realize that plan, Eggman teamed up with Modern Eggman and began helping him lure Sonic and Modern Sonic into Modern Eggman's traps.

Eventually, Sonic and Modern Sonic, along with Tails and Modern Tails, tracked Eggman and Modern Eggman down to their lair. There, the heroes found out about the Time Eater's true origin when the doctors revealed themselves and their plan, intending to dispose Sonic from time (although Eggman ended up disturbed that he might become crazy when witnessing Modern Eggman breaking down into hysterical laughter). The Eggmans proceeded to attack the Sonics with the Time Eater, and managed to knock them out. However, both Sonics would transform into Super Sonic when their friends showed up to cheer them on. After enduring an intense battle, Eggman and Modern Eggman ended up being defeated when the Super Sonics destroyed the Time Eater, which undid all of their work on rewriting history.

Finding themselves stuck in the White Space, Eggman and Modern Eggman went about looking for a way out. After arguing about whether or not they would ever win, Eggman thought that maybe he should instead pursue his "teaching degree" after these events, to which Modern Eggman agreed as he enjoyed telling people what to do, much to Eggman's exasperation.

Sonic the Hedgehog 3 & Knuckles
In Sonic the Hedgehog 3 & Knuckles, Eggman crash-landed on Angel Island in his Death Egg. There, he tricked Knuckles the Echidna, the guardian of the island and its Master Emerald, to keep Sonic and Tails off his back while he repaired the Death Egg. When Eggman re-launched the Death Egg however, the space station was brought down to Angel Island again by Sonic and Tails. Having not given up let however, Eggman stole the Master Emerald and used it to re-launch the Death Egg again. However, Eggman soon after got defeated by Sonic and Tails, who destroyed the Death Egg.

Sonic Mania
In Sonic Mania, after Sonic and Tails had defeated Eggman, the evil scientist detected a strong energy source coming from Angel Island, prompting him to send his five elite Egg-Robos, the "Hard Boiled Heavies", to go and retrieve the source. Soon, Eggman found himself in Green Hill Zone, where he faced Sonic, Tails and Knuckles in his Death Egg Robot. He was soon defeated though, and eventually came across his newly upgraded Hard Boiled Heavies. Seeing as the Heavies would no longer listen to him, Eggman stole the energy source, the "Phantom Ruby", away from them and used its power to send Sonic, Tails and Knuckles, who were secretly eavesdropping on him nearby, away.

Over the next period, Eggman used the ruby to restore Little Planet to its mechanized state. There, he built a robotic fortress known as the Titanic Monarch. Along the way, Eggman made several attempts to stop Sonic and co., but was defeated each time. He would also use the ruby to displace the heroes at different places in space-time.

It was not long until Sonic, Tails and Knuckles chased Eggman down to his base. However, the mad doctor was prepared for them. He fought the trio using his Phantom Egg while sending the heroes to also fight the members of the Phantom Heavies. Unfortunately for Eggman, he was still defeated. Upon his defeat however, the Phantom Ruby sent Eggman and Sonic to an unknown location. There, the Phantom King (the upgraded leader of the Hard Boiled Heavies, the Heavy King), stole the ruby for himself. Eggman was not prepared to give up easily though, and used his Klepto Mobile to combat his traitorous minion. In response, Sonic used the Chaos Emeralds to transform into Super Sonic to fight them both. After the Phantom King was defeated, Eggman was delivered the final blow by Super Sonic, putting his mech and his plans to ruins.

Sonic Forces
In Sonic Forces, Eggman makes a cameo appearance. In this game, his face can been on the Goal Plates in the Classic Sonic stages until the player passes them, at which point his image will be replaced with one of Classic Sonic.

Personality
Much like Modern Eggman, Dr. Eggman is a short-tempered, raucous, pompous, cruel, immature and evil genius who uses his scientific mind to create weapons and gadgets in his bid to take over the world and build "Eggman Land." His primary motivation is his psychotic belief of self-entitlement. Arrogant and narcissistic, he constructs countless technological wonders in his own image to fuel his massive ego, like the Death Egg and the Death Egg Robot.

In comparison to Modern Eggman, Eggman is more calm and collected. This is because Eggman's sanity has yet to deteriorate from years of defeat at the hands of Sonic the Hedgehog. Having seen Modern Eggman's bouts of craziness himself, Eggman worries that he will one day go crazy too.

Powers and abilities
Possession an astonishing IQ 0f 300, Eggman has proven himself to be just as intelligent as Modern Eggman. His most well known ability is his masterminded plots and schemes which only fail due to Sonic and his friends. He is a remarkable scientist and engineer, as evidenced by the numerous armies of robots, warships, and other mechanical inventions he has created. Eggman is also an incredibly skilled pilot; able to swoop missiles and lasers in his various creations and vehicles.

Classic Sonic
Eggman has many enemies, but his arch-nemesis is none other than his world's Sonic the Hedgehog, who always thwarts the doctor's evil plans for world domination. In fact, Eggman despises Sonic so much that for all his goals about dominating the world, his one true desire appears to be besting Sonic, having confirmed that this is his definition of a victory.

Modern Eggman
Modern Eggman is Dr. Eggman's future counterpart from another dimension. When they met each other, the two of them worked together as partners to dispose of their respective Sonics. At first, it was evident that Eggman held a distinct respect for Modern Eggman, having referred to him as a "gentleman genius". However, it soon became apparent to Eggman that his modern counterpart was a few bolts short of a robot after seeing him break down into a hysterical laugher, which made Eggman worry about whether or not he was destined to end as him one day. Furthermore, Eggman disliked being left out of Modern Eggman's rants, like when Modern Eggman gloated about destroying the Sonics himself when they were supposed to do it together. Their relationship further deteriorated after their shared defeat at the end of the Time Eater incident, which prompted them to argue more frequently. Eggman in particular lost all respect for Modern Eggman, particularly after learning that he never once defeated Sonic.

Allies

 * Metal Sonic
 * Modern Eggman
 * Time Eater

Enemies

 * Amy Rose
 * Blaze the Cat
 * Chaotix
 * Charmy Bee
 * Espio the Chameleon
 * Vector the Crocodile
 * Cream the Rabbit and Cheese
 * Knuckles the Echidna
 * Miles "Tails" Prower
 * Modern Knuckles
 * Modern Sonic
 * Modern Tails
 * Rouge the Bat
 * Shadow the Hedgehog
 * Silver the Hedgehog
 * Hard Boiled Heavies
 * Heavy King
 * Heavy Gunner
 * Heavy Magician
 * Heavy Shinobi
 * Heavy Rider