Hank McCoy was born a mutant, with heightened agility and the ability to use his feet as well as his hands. He was also cursed, however, with a disproportionate body. He has huge apelike hands and feet, and quite often feels more comfortable walking like a primate instead of upright like a man. He has a brilliant mind, loves studying sciences, and he is often heard quoting Shakespeare. Hank is a serious campaigner for mutant rights, having known intimately the pangs of being an outcast. The Conquistador forced Hank to steal a portable nuclear device in college, and was soon rescued by his future friends in the X-men. His cheery outlook and puckish charm has kep him relatively sane all these years.

Hank was a founding member of the first group of X-Men, with the Angel, Cyclops, the Iceman, and Marvel Girl. Together they fought the first mutant foes and world menaces. But Hank desired to get a doctoral degree at the University, so he left the group and became a brilliant doctor in biochemicals. During the course of his works, Hank found out that one of his experiments, a chemical that induced mutations, was about to be stolen. He drank it down, turning into a beast-looking being, his body covered by blue hair and growing large canine teeth. His own powers then became increased, but thankfully his mind kept intact.

During a brief period, he joined the Avengers, but returned much later with the X-Men. During his hiatus from the X-Men, he spent some time with the first X-Factor team, when they still pretended to be mutant hunters. He recovered his human form for some time, using information from Dr. Carl Maddicks that he was to give Maddick's son. Unfortunately, after being kissed by Infectia, the Beast began to lose intelligence, losing it even more quickly whenever he used his powers. During the first confrontation with the Smilefaces of Hodge from The Right (just at the beginning of Inferno), Apocalypse's former ship returned him to his blue form and to the top of his intelligence.

He rejoined the X-Men after the Shadow King crisis, and is currently working with Moira McTaggert and Xavier on the Legacy virus.