Nancy Crater is the wife of archaeologist Robert Crater and accompanied her husband to planet M-113 in 2261. She was killed roughly three years later by the last surviving, salt-sucking creature native to that planet. The creature used its hypnotic powers to appear to Prof. Crater as Nancy, giving him companionship in return for a steady supply of salt. In 2266, the creature also appeared as Nancy to Leonard McCoy, who had been romantically involved with Nancy ten years prior.