A hero published by Marvel Comics and created by Steve Ditko. Speedball first appeared in Speedball, the Masked Marvel #1 in 1988.

Robbie Baldwin was the son of Justin and Madeline Baldwin. While working as a lab assistant in Hammond Research Lab, Baldwin was exposed to a weird form of extra-dimensional energy that caused him to be surrounded by a field of bubbles. These bubbles had a number of effects with the main one being that they acted as a force field around Baldwin. The field returned kinetic energy directed against it back at the source, but in greater quantity. Hence if Baldwin is hit by an object, it is deflected and at a higher speed than it struck him. The net effect was that Baldwin is unable to be physically harmed when the field is active. Because of the nature of the field, if Baldwin strikes something, he bounces back. This causes him to bounce around with very little control as to his direction and speed.

Baldwin also gains physical mass from the field appearing taller and larger when the field is active. It also covers Balwin with a costume and causes his hair to stand up, as well as giving Baldwin's voice a hollow sound.

Baldwin initially spent a good deal of time trying to keep his new abilities as secret. He adopted the name Speedball the Masked Marvel when the field was active and fought a number of villains. He also spent time chasing a cat named Niels who had also been exposed to the strange energy, hoping that experiments on the animal would allow him to control his new abilities.

When Night Thrasher was collecting a group of teen heroes to aid him in a personal quest, the group found themselves opposing the former herald of Galactus, Terrax the Tamer. Their battle was televised and Baldwin went to the scene to aid in the battle as Speedball. The other members of the group allowed him to join the group and the New Warriors were born.

Over the years, Baldwin gained more control over his ability and learned to project his field to protect others and a number of other effects. Speedball also learned to control his path while bouncing.