- Leonardo (Cam Clarke)
- Donatello (Barry Gordon)
- Michelangelo (Townsend Coleman)
- Raphael (Rob Paulsen)
- Splinter (Peter Renaday)
- April O'Neil (Renae Jacobs)
- Vernon Fenwick (Peter Renaday)
- Professor Lloyd Cycloid (Hamilton Camp)
- Museum Curator (Rob Paulsen)
- Scientist (Cam Clarke)
- First Policeman (Townsend Coleman)
- Second Policeman (Maurice La Marche) ???
Donatello makes a machine that can stop time and it is stolen by Professor Lloyd Cycloid steals it and plans on using it to steal priceless items, now the turtles must stop him.
- Turtles' Lair
- Professor Cycloid's house
- Time Stopper
- Laser Cutting Machine
- Cycloid Satellite
Home media releases
- Teenage Mutant Ninja Turtles: Donatello's Degree
- Teenage Mutant Ninja Turtles Season 4
- Teenage Mutant Ninja Turtles: The Complete Classic Series Collection
- The Turtles' weapons did not made a clashing sound when they and the Turtles fell to the floor after the effects of the Time Stopper wore off.
- The Time Stopper was drawn mirror-flipped during the final scene.
- The mushrooms on Michelangelo and Raphael's pizzas were colored red in the final shot at the tail end of the episode.
- When Leonardo spoke to Donatello on the Turtlecom at Cycloid's house he was seen with Raphael's sai.
- When the turtles are frozen after the commercial, they are in different positions.
- When April is interviewing the scientist, the tip of her microphone vanished.
- When Donatello is watching the rays from Cycloid's malfunctioning laser cutter, the knob on the lab door is missing.
- The tips of Raphael's sais were missing when Donatello said that the Time Stopper could be dangerous in thw wrong hands.