Though Hammer, Foster, Sterig, and Marshak had been planned to be performed by a sole actor using different makeup, the production crew timed the planned scene and noted his time wearing makeup would exceed that of him in front of the camera, so four actors were used.
Among a handful of TZ episodes to exclude the series title in the closing narration. Other episodes to do this include Jess-Belle (1963) (which had no closing narration at all), Long Live Walter Jameson (1960), On Thursday We Leave for Home (1963), and He's Alive (1963).
This is the first instance in where Phillip Pine's character's identity is usurped. The second being The Hundred Days of the Dragon (1963).