As a child, Christopher Annex had a traumatic childhood with alligators. On the planet White, he was nearly killed by a giant crocodile and was left scarred for life - physically and emotionally. To hide his natural shyness, he adorned the "Beastman" persona and adopted the outfit of a dinosaur to give himself an imposing figure. His deadly sharpshooting skills and aggressive tendencies made him feared by the beasts he hunted. His beast hunting has made him quite popular and a hero to many people.
Once he had eliminated all of the dangerous creatures from his home world, he decided to enter the F-Zero Grand Prix to promote himself for anybody wishing to employ his services. It was during his first year of racing that he met Bio Rex, a new competitor designed by the Keerlon Corporation. Beastman has since continued to compete in the Grand Prix with a vow to protect the other pilots and crowd from Bio Rex in case the creature ever decides to go rogue.