Beak is a mutant whose body has taken on the characteristics of a bird. His bones are light and hollow and his arms have begun to grow feathers which, when fully formed, may allow him to fly. He can currently glide and fly for short distances with great effort. Beak also has enhanced eyesight along with sharp talons on his hands and feet.

Despite Beak's obvious mutation, his father's standing in the Human Council was enough to keep him out of the Dark Beast's Breeding Pens for most of the Age of Apocalypse. However, after the Sinister's departure, the Dark Beast sent out agents to retrieve all known mutants for his upcoming experiments. Beak was captured and promptly labeled a "reject." During their attack on Apocalypse's Kingdom, Magneto and the X-Men found the boy leading a small band of injured rejects to freedom. Magneto returned Beak to his home, but was impressed by the boy's optimism in the face of certain death. Many X-Men saw Beak's appointment to the team as a political favor to Beak's father who currently serves on the Unites Sates government. However, Magneto truly believed in this young mutant, but whether or not Barnell Bohusk believes in himself his unknown.

His two closest friend in the X-Men would be Xorn and Wolfsbane. After Xorn appeared to be fatally wounded in battle against the Morlocks, Beak and Wolfsbane went to visit her in the infirmary. Beak was happy to report that the ones who had done this to her had been caught and were downstairs in holding. Wolfsbane thought they should go down and teach the Morlocks a lesson for what they did, but Xorn asked them to think about how they would react to strangers who seemed to be trying to take them back to captivity, having been trapped themselves in Sinister's lab not too long ago. They surely would have fought back against the X-Men as well. While Wolfsbane was aware of this, she was only trying to make Xorn feel better. However, Beak had never thought of it this way before and Xorn urged him to try and look at both sides to every story. Beak was last seen participating in a recreational football game the X-Men had during some off-time.