Sometime after 1972, NASA astronaut, Captain Steve Cory of the Apollo X, crashed landed on Hinrichs V in a capsule. After landing, Cory's DNA was rewritten, changing him into a creature. For three hundred years he survived.
In 2261 of the alternate reality, the USS Enterprise under Capt. James T. Kirk, on its first five-year mission, led an away team to explore the planet. However, Kirk's and Spock's teams were attacked Cory in his creature. Kirk then returned and then had Cory beamed up to the Enterprise where he changed back to his human form. However, Capt. Kirk was forced to return Cory back to the surface when he started to died. Starfleet then sent a medical to monitor Cory and hopefully find a cure for him.(TOS - Lost Apollo comics: "Part 1", "Part 2")