Leonardo Lightens Up
1987 TV series episode
Season Code: 4
Episode: 19
Original airdate
Written by
Episode chronology
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"Donatello Makes Time" "Funny, They Shrunk Michelangelo"
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Teenage Mutant Ninja Turtles 1990 Season
September 8, 1990 - December 1, 1990
List of Teenage Mutant Ninja Turtles episodes


  • Syndication
  1. "Plan Six From Outer Space"
  2. "Turtles of the Jungle"
  3. "Michelangelo Toys Around"
  4. "Peking Turtle"
  5. "Shredder's Mom"
  6. "Four Turtles and a Baby"
  7. "Turtlemaniac"
  8. "Planet of the Turtles"
  9. "Name That Toon"
  10. "Menace Maestro, Please"
  11. "The Turtles and the Hare"
  12. "Once Upon a Time Machine"
  13. "Rondo in New York"
  14. "Superhero for a Day"
  15. "Back to the Egg"
  • Saturday Mornings
  1. "The Dimension X Story"
  2. "Son of Return of the Fly II"
  3. "The Big Zipp Attack"
  4. "Farewell, Lotus Blossom"
  5. "The Big Cufflink Caper!"
  6. "Rhino-Man"
  7. "Were-Rats from Channel 6"
  8. "Bebop and Rocksteady Conquer the Universe"
  9. "Slash - The Evil Turtle from Dimension X"
  10. "Rebel Without a Fin"
  11. "Poor Little Rich Turtle"
  12. "The Foot Soldiers are Revolting"
  13. "Big Bug Blunder"
  14. "Donatello's Degree"
  15. "Raphael Meets His Match"
  16. "Raphael Knocks 'em Dead"
  17. "Donatello Makes Time"
  18. "Leonardo Lightens Up"
  19. "Funny, They Shrunk Michelangelo"
  20. "Michelangelo Meets Bugman"
  21. "Leonardo Versus Tempestra"
  22. "What's Michelangelo Good For?"
  23. "Beyond the Donatello Nebula"
  24. "Unidentified Flying Leonardo"
  25. "Raphael Drives 'Em Wild"
  26. "Splinter Vanishes"

1987 Season1988 Season1989 Season1990 Season1991 Season1992 Season1992-1993 Vacation in Europe sideseason1993 Season1994 Season1995 Season1996 Season

Leonardo Lightens Up is a season 4 episode of the 1987-1996 series.


Splinter is away, leaving Leonardo in charge. Unfortunately, he's having trouble keeping his brothers in line with their ninja exercises: Raphael watches TV, Donatello works on his inventions, and Michelangelo makes pizza. All three tell him to "lighten up."

Raphael suggests that they should use the personality modifier ray on Leonardo, despite Donatello's protests that it isn't perfected. As they scuffle over it, they accidentally fire it at Leonardo - and discover that his personality has been changed to carefree and irresponsible.

Meanwhile, some goons are setting up giant speakers atop a building, on behalf of the villainous Maestro G. Cleff, who uses sound waves to cause chaos. April and Vernon attempt to cover the story, only for their equipment to disintegrate and buildings to start collapsing. While the mayhem is going on, Cleff's goons are robbing the treasury. April manages to escape into the sewer, and heads for the lair.

Leonardo's new lighthearted approach is grating on the other Turtles, as he serves them an exploding turkey and sprays them with water. April arrives and tells them about Cleff, which motivates them to turn him back to normal. Unfortunately, Leonardo has already left to "enjoy himself" at the beach.

Cleff uses his speakers to rob another bank, planning to use the money to build even more powerful speakers.

The Turtles manage to find Leonardo sunning himself, and he dismisses their concerns about the "mad Maestro." They try to tackle Cleff without Leonardo, wearing special protective helmets, but the music is loud enough that the helmets simply explode and the Turtle Blimp plummets to the ground.

They realize they need Leonardo, and track him down where he's skateboarding. They try to capture him, but his ninja skills are undiminished by his new mindset.

Just then, Splinter returns home and hears what they have been doing since he left. His idea is to challenge Leonardo to a skateboarding contest, and if he wins, Leonardo must return to the lair. Splinter manages to subdue him, and Donatello uses the ray to return Leonardo to his usual bossy, hyper-responsible mindset.

The reunited Turtles confronted Cleff, and don earmuffs to block out his devastating music. Leonardo easily destroys his keyboard and Michelangelo wrecks the giant speakers.

Cleff and his henchmen are arrested, and Splinter reminds the Turtles that all kinds of people are needed in the world, including ones like Leonardo.





  • Turtlecom
  • Personality Alterator
  • G.Clef's Super Stereo
  • Soundproof helmets

Home media releases


  • Teenage Mutant Ninja Turtles: Leonardo Lightens Up


  • Teenage Mutant Ninja Turtles Season 4
  • Teenage Mutant Ninja Turtles: The Complete Classic Series Collection



  • When Raphael takes the television remote from Leonardo, the close-up shot shows Leonardo's hand changing the channel, when Raphael has the remote.
  • When Donatello told Leonardo he had to get back to his workshop, the background showed a plastered and painted wall instead of the normal sewer brick wall.


  • First appearance of Donatello's Personality Alterator device.


  • Man: Hey that's gotta be the loudest sound I ever heard!!
  • Woman: What? I can't hear you! Someone's making the loudest sound I ever heard!!
  • Man: I'm getting outta here!!
  • Woman: Not me! I'm getting outta here!!
  • Michelangelo: Whoa, I am one hungry turtle!
  • Raphael: Yeah. *whistle* Hey, Leonardo, where's our dinner?
  • Leonardo: *in a French accent* Voila! Ho ho ho, le diner, is, how do you say, she's a served!
  • Donatello: Great, roast turkey! *The turkey explodes*
  • Leonardo: *laughs* Oh, you guys oughta see yourselves! What a bunch of... of turkey-covered... turkeys! *Still laughing*
  • Donatello: You're a real barrel of monkeys, you know that Leonardo?
  • Michelangelo: Yeah, dude! That exploding turkey was a total YUCK!
  • Raphael: "Yuck" is the perfect word.
  • Donatello: Who's gonna clean up this mess?
  • Leonardo:*French accent* Never fear, monsieur! I will take care of it to a suite! *pulls out a water tank and sprays the turtles* How do you say in my country: Au reservoir! *laughs* Get it? *Laughs a little more, then runs away*


External links