Dr. Eggman Nega/Pre-SGW

Dr. Eggman Nega, also known as Dr. Nega, is a mysterious villain and "mad man" who went to war with the Zone Cops. Traveling across the Cosmic Highway, Nega's actions caused severe chaos across the multiverse. For this reason, the Zone Cops issued a lock-down on the various universes, leaving only a few open to maintain stability. Nega's war with the Zone Cops resulted in massive damage to No Zone. He is rumored to be after the Sol Emeralds and the Jeweled Scepter.

Early History
Little of Nega's early history is largely known, with several details suggesting he either comes from 3437 P.X.E. or Blaze's world. Whatever his origins, he is known to have actively sought out the Sol Emeralds, and possibly the Jeweled Scepter as well. (CSE)

Sonic the Hedgehog, Miles "Tails" Prower, Blaze the Cat and Marine the Raccoon had a brief encounter with Dr. Eggman Nega while fighting against Captain Whiskers and Johnny in Blaze's home world. (SU: #1)

War with the Zone Cops
Demonstrating the intelligence necessary to leave the Sol Zone, Nega became involved in a war with the Zone Cops, which resulted in a great deal of damage to the No Zone and a lockdown of the Cosmic Interstate. Dr. Nega would later fly an insect-like aircraft carrying a mysterious capsule containing the Cyan Sol Emerald to the Prime Zone using a portal while being chased by two Zone Cop vehicles. The Zone Cops attempted to arrest him on charges of illegally crossing 47 Zones, but Nega refused to be taken into custody. As he fired at the Zone Cops, one of them fired at the craft's legs, dislodging the capsule. Nega then escaped the Prime Zone using another portal, with the Zone Cops still in hot pursuit. (StH: #189, #197, SU: #21)

Personality
Malevolent and power mad, Eggman Nega's greatest weapon is his vast intellect and technological genius. Based on his success both in departing the Sol Zone and in waging a veritable one-man campaign against the Zone Cops, it is believed that he is the equal if not superior of Dr. Eggman.

Appearance
His design appears reminiscent of the older Dr. Eggman from the Genesis era, albeit with the colors reversed, a longer nose, a white mustache (suggesting he is at an elderly age), pointy blue sunglasses, and visor-styled goggles instead of normal ones.

Background information

 * Dr. Nega was never referred to by name in Sonic Universe #1, though his silhouette can be seen in the issue, and notably, he appears to have a similarly shaped body to that of Dr. Eggman. It was only hinted that he was Dr. Nega in one of the caption boxes in Sonic the Hedgehog #197.
 * Dr. Nega's full name is Eggman Nega. However his appearance and full name are currently limited in the comics due to issues with SEGA, but Ian Flynn hopes that that will be rectified in the future. (1)
 * Fans often debate if the Eggman Nega from the Sonic Rush series is the same as the one from Sonic Rivals or is a completely different person. They have entirely different origins, he is Dr. Eggman's alternate counterpart in Sonic Rush and in Sonic Rivals he is his descendant.
 * Curiously, the characters that don't find out about Eggman Nega's "future" origin in the Sonic Rivals series consist of only the characters that have knowledge from the Sonic Rush series about his "dimension" origin.
 * In the Sonic Boom 2012 event, Takashi Iizuka has offically stated that Eggman Nega and Silver are from the future.
 * Dr. Nega made in unofficial appearance in Sonic Universe 24's Off-panelDr._Nega-Off-Panel-1-.jpg, in which he talks with Sonic on how they received limited appearances in the arc.
 * Dr. Eggman Nega was finally officially revealed in The Complete Sonic Comic Encyclopedia. His page stated that his origins were unknown, a nod to his dual origin story.