Sam was a male Human Starfleet crewman who lived during the mid-23rd century. He served aboard the USS Enterprise in 2266 under the command of Captain James T. Kirk, during Kirk's historic five-year mission.
In that year, Sam and Kirk demonstrated some basic self-defense and throwing techniques in the ship's gymnasium for Charlie Evans, a young man whom the Enterprise was transporting to Earth Colony 5. Charlie then became frustrated with his inability to master the same techniques. When Sam began laughing at the boy, he was sent to "oblivion" by Evans, utilizing incredible psychokinetic abilities granted to him by the Thasians.
This uncredited role was played by regular series stuntman Robert Herron, although the cast sheet, dated 8 July 1966, names the part of "Stunt (Sam)" as Beau Vandenecker. This information is also referenced in the Star Trek Concordance.
In the script and episode, the character was named "Sam". The final draft script also characterized him as an officer.
In the novelization "Charlie's Law" by James Blish (released by Bantam Books), he was referred to as "Sam Ellis", an officer, who was part of McCoy's medical staff. Of note, a seemingly out-of-place lexicon entry for a "Mr. Ellis" also appeared in the Concordance; however, the corresponding text referred rather to Tom Nellis.
The Errand of Vengeance novels name this character "Sam Fuller".