Ben is a giant mechanical rat that is slightly taller than an average human. Its main body is purple, although its ears and tail are in a lighter shade while its wheels, arm joints and ear joints are in a darker shade, and its eyes are completely red. In the centre of its body, it has a silver/gray metal plate. It is equipped with a purple strap on its back resembling a jetpack with rockets.
As part of Dr. Eggman's plan to rob the Twelfth National Bank of Station Square, he summoned Ben from his Selection Machine to aid him. Ben and Eggman soon after broke into the bank with the doctor demanding money. Most of the civilians, including Sonic's friends were at the bank ran to take cover as Ben blasted the bank with its weapons. Mr. Tanaka tried to fight it off but Ben knocked him away with its tail.
As Ben was ordered to open the vault, Amy struck Ben with her Piko Piko Hammer which caused Ben to accidentally fire its missiles at Eggman. The doctor then ordered Ben to attack Amy and Tails but then Sonic arrived to aid his friends. Focused on its new target, Ben attacked Sonic but the hedgehog dodged him and with the aid of a Ring, struck Ben with his Spin Attack multiple times, destroying it.
- The robot's name and design is a reference to the 1972 horror film Ben about a boy and his pet rat. The film is notable for including a song of the same name sung by Michael Jackson over the end credits. After introducing the robot, Eggman sings a variation of a line from the song.