A villain published by Marvel Comics. The Rhino first appeared in Amazing Spider-Man #41 in 1966.

Alex O'Hirn was a small time crook with lots of muscle and little on his mind. He had fallen in with a bad crowd and was employed by several New York gangs as hired muscle. That was until he was approached by a group of ambitious criminals with a plan to create a super-powered enforcer.

The group selected O'Hirn because of his superior strength and substandard brains, thinking that he would be easily manipulated. O'Hirn agreed to take part in their schemes and was subjected to a number of experimental treatments to boost his strength to super-human levels. O'Hirn was then outfitted with a tight fitting suit of extremely durable grey material that deflected bullets and allowed O'Hirn to use his strength without fear of physical injury. Finally, the suit was equipped with a horn on the head, giving O'Hirn the appearance of a rhinoceros, and was dubbed the Rhino.

The first mission for the new enforcer was to kidnap the son of newspaper publisher J. Jonah Jameson and hold him for ransom. The Rhino decided that he was uninterested in splitting the money from the crime and turned on the group that gave him his powers. He then attempted to kidnap John Jameson, but ran afoul of Spider-man. The two fought and the Rhino was defeated and sent to jail, where his strength was kept in check by keeping him sedated.

Eventually, the Rhino escaped and fought again with Spider-man, the two becoming regular foes. The Rhino later had his strength boosted by the Leader and fought the Incredible Hulk. He was defeated and soon found that his costume had been afixed to his skin so that he could not remove it. Fearing that he would forever be stuck with this freakish appearance (not to mention the hygenic issues of being trapped in a one piece outfit), he sought help in removing the suit, during which time he clashed with Ben Grimm, also known as the Thing.

The Rhino eventually had the suit successfully removed, but commissioned another from master criminal Justin Hammer. The new suit was superior to his original and O'Hirn continues to use it to this day.