Arriving at the "amusement park" planet for some relaxation, the
Enterprise finds that the
planet's keeper is now dead and the untended machinery is constructing dangerous images
from the crew members' thoughts.
- This episode was a sequel to the Original STAR TREK series episode
"Shore Leave" by Theodore Sturgeon.
- A scene in this episode showed the interior of the Enterprise hanger deck. Visible in the hangar deck was
a heavy shuttle (as seen in "Mudd's Passion"), and a
long range shuttle (as seen in "The Slaver Weapon").
- In this episode, the date of the Caretaker's death could be read off of the gravestone: 7009th year of operation.
- An accomplished singer, Nichelle Nichols as Lieutenant Uhura, sang in this episode as she had done in a
number of original STAR TREK episodes. In this episode, she vocalized for almost 40 seconds.
- This episode's co-writer, Chuck Menville, also wrote another animated STAR TREK episode
"The Practical Joker". Chuck Menville, along with Len Janson, also wrote for several other Filmation series from 1969 to 1976.
- There is a page in this site that examines the Hover Robots
that were seen in this episode.
- In this and other episodes, the sciences insignia erroneously appeared on red shirts.
- The correct spelling of this episode's co-writer is Janson. All episode guides of the animated
STAR TREK universally mispell his name as Jenson.
- This episode had a visual error: the hangar deck doors opened from one side, while in the animated episode
and the original series, the doors open from the center like a sideways clam shell.
- Another visual error: McCoy's tricorder strap disappeared in a bridge scene.
- This episode had another mistake in which Sulu was erroneously shown calmly sitting on the bridge
while he was actually imperiled on the planet's surface.
- A VHS video tape containing "Once Upon a Planet"
and "The Eye of the Beholder" is available for purchase from
amazon.com, the online bookseller.
- "Once Upon a Planet" was novelized by Alan Dean Foster in Star Trek Log Three
published by Ballantine Books in January 1975. Also novelized in the book was
"The Magicks of Megas-Tu" and "Mudd's Passion".