In 2285, Croy, along with the bulk of the Enterprise's senior staff, participated in a number of Kobayashi Maru scenarios for Starfleet Academy cadets at the main Academy test center in San Francisco. During these simulations, Croy acted as the ship's navigator alongside Lieutenant Commander Hikaru Sulu. (TOS novelization: Star Trek II: The Wrath of Khan)
Later, Croy returned to the real Enterprise for a training voyage, and was later on the bridge during the attack on that ship by Khan Noonien Singh. (TOS movie & novelization: Star Trek II: The Wrath of Khan)
In an alternate timeline created by Spock's death as a child, Croy also served on the Enterprise during an attack by Singh. He would later be promoted to Lieutenant after the destruction of Starfleet Academy. (Myriad Universes - Echoes and Refractions novel: The Chimes at Midnight)
- Unnamed USS Enterprise (NCC-1701) personnel#Trainee lieutenant junior grade article at Memory Alpha, the wiki for canon Star Trek.