Omega Shogan is a robot Sirocco built right after joining up with Robotnik.

Omega Shogan has a plasma gun, which is useless when it's by itself. When Omega Shogan attaches the gun to one of it's arms it gains power and then can fire plasma beams.

Omega Shogan is also a large robot being larger than Robotnik himself in height. The only person who matches Shogan's height is Prince Ricardo.