An Enterprise crewman killed on planet M-113 in 2266 by the shape-changing salt creature, which then took his appearance to beam aboard the ship and hunt among the crew.
Crewman Green appears in The Man Trap, the first episode of the series to be broadcast. He beams down to M-113 with Kirk, McCoy and Crewman Sturgeon when the captain returns to question Professor Crater about the death of Darnell.
While the officers are occupied, the creature posing as Nancy Crater kills both Sturgeon and Green by draining the salt from their bodies. It then assumes Green's form and joins Kirk and McCoy for the beam-up, leaving his real body hidden on the surface.
As Green, the creature wanders the corridors in a daze of hunger, trailing Janice Rand for the salt on a meal tray and disturbing the plants in the botany laboratory where Sulu is working, before changing shape again. He was played by Bruce Watson.