E-123 Omega's design appears to be based on the rest of the E-100 Series robots (particularly E-102 Gamma) while making him stand out by giving him a stockier upper body and arms with red eyes instead of green. He is also much shorter than the other models and his shoulders are much larger with a visible Greek symbol on the front of the left and back of the right with red handlebars on the top. Also, instead of the twin exhaust pipes and the Jet Booster of the first E-100 Series robots, Omega has one circling pipe around the waist with two flaps attached and having twin jets installed in his back below the hunch.

Omega's only goals in life are to take revenge on Eggman for wasting his potential and destroy the doctor's other robots to prove himself superior. These two goals are absolute above all else in Omega's eyes. As a result, he tends to be extremely headstrong and reckless, unlike his teammates on Team Dark who have more common sense. In Sonic Forces, he performs what is supposed to be a recon mission on Eggman's base, and, rather than sneaking in to get information, storms in guns blazing in an effort to purge the base of every robot within, despite his orders having nothing to do with extermination. At one point in Shadow the Hedgehog, Omega made a comment about how he would "reign supreme". Some fans have taken these words quite literally, and believe that Omega wants to take over the Eggman Empire and become a robot overlord in the style of Metal Sonic. However, subsequent games have shown this less believable, and it is generally taken to mean that he wishes to prove himself as the greatest of Eggman's robots.

Vocal Direction (Jon st John)