Final answer:
The individual mentioned in the Gospel of John during the appearances of the resurrected Christ that is not mentioned in the other gospels is Thomas.
Step-by-step explanation:
The individual mentioned in the Gospel of John during the appearances of the resurrected Christ that is not mentioned in the other gospels is Thomas. In John 20:24-29, it is described how Thomas expressed doubt when some disciples claimed to have encountered the risen Christ. He stated that unless he sees the mark of the nails in Christ's hands and puts his finger in the mark of the nails and his hand in Christ's side, he will not believe. However, a week later, Jesus appears to Thomas and invites him to touch his wounds, and Thomas exclaims: 'My Lord and my God!'