Guard Robo

Guard Robos are robots built by Doctor Eggman in the video game Sonic Battle.

History
According to Rouge the Bat, Eggman built these robots to sell them and make some extra cash. They are encountered numerous times in the game in areas such as Central City and Night Babylon, where they are protecting such areas as a lab, a bar, a casino, etc. Rouge also uses them as practice robots when she's training Emerl to be a master thief. They appear to resemble Chaos Gamma, and have the same attacks and almost the same look. Guard Robos are unable to speak during battle, making it harder for the player to avoid the explosion that happens upon defeat.

Trivia

 * Guard Robos are similar to the E-121 Phi robots, both being black/gray/white, and they are both a copy of someone else (Guard Robo being a copy of Gamma and Phi being a copy of Emerl).