Leonardo is a fictional character portrayed by Jason Biggs in the TV series Teenage Mutant Ninja Turtles.
In the first episode they appeared in, titled Rise of the Turtles: Part 1 (season 1), they were 34 years old.
They appear in 44 episodes out of a total of 124 aired and have accumulated 51 positive votes.
The character of Leonardo is mainly associated with Raphael and Splinter.
Leonardo is also portrayed by Seth Green and Dominic Catrambone.
Episodes44
Rise of the Turtles: Part 1
episode S1.E1 september 2012When Splinter allows his teenage sons, the Mutant Ninja Turtles, to visit the surface for the first time, they discover that the surface world isn't as simple as it first appears.
Rise of the Turtles: Part 2
episode S1.E2 september 2012When Splinter allows his teenage sons, the Mutant Ninja Turtles, to visit the surface for the first time, they discover that the surface world isn't as simple as it first appears.
Turtle Temper
episode S1.E3 october 2012The turtles are caught on a mobile phone's camera and must retrieve it. This is complicated by the phone's obnoxious owner, who constantly provokes Raph into losing his temper.
New Friend, Old Enemy
episode S1.E4 october 2012To prove that Turtles can be friends with humans, Michelangelo uses a social networking site to befriend Chris Bradford, a famous martial artist.
I Think His Name Is Baxter Stockman
episode S1.E5 october 2012When the Turtles sneak out against Splinter's wishes, they run afoul of Baxter Stockman, a deranged inventor in mechanical battle armor.
Metalhead
episode S1.E6 october 2012Weary of using his simple bo staff to fight the technologically advanced Kraang, Donatello creates Metalhead, a remote-controlled robot turtle to fight in his place.
Monkey Brains
episode S1.E7 november 2012Donatello and April investigate a scientist's disappearance, but discover a conspiracy regarding a bizarre psychic monkey instead.
Never Say Xever
episode S1.E8 november 2012Leo fears his act of mercy has come back to haunt him when Xever holds a local noodle shop owner hostage.
The Gauntlet
episode S1.E9 november 2012After April receives a warning from her imprisoned father, she and the Turtles embark on a mission to save him and stop the Kraang from detonating a mutagen bomb in the city.
Panic in the Sewers
episode S1.E10 november 2012The Turtles must defend their home in the sewers when Bradford tries to destroy it with a dangerous chemical.
Mousers Attack!
episode S1.E11 december 2012When simultaneous threats from the Purple Dragons and Baxter Stockman's mechanical Mousers force the Turtles to split into two groups, Donnie & Mikey must prove that their "B Team" is just as valuable as Leo & Raph's "A Team."
It Came from the Depths
episode S1.E12 december 2012Michelangelo befriends an unstable mutant alligator who possesses a strange piece of Kraang technology, but the other Turtles aren't sure whether Leatherhead is a friend or a foe.
I, Monster
episode S1.E13 january 2013The Turtles must face off against a new enemy, The Rat King, who threatens not only to take control of the city, but Splinter's mind as well.
New Girl in Town
episode S1.E14 february 2013Leonardo, tired of Raphael's constant criticism, lets his brother try his hand at leadership for a while. Meanwhile, Leonardo meets a beautiful and dangerous female ninja who tries to lure Leonardo to the dark side.
The Alien Agenda
episode S1.E15 february 2013The Turtles get their first taste of high school when April's school project draws Kraang attention.
The Pulverizer
episode S1.E16 february 2013The Turtles meet their first fanboy when a teenage wannabe hero decides to fight crime and dress up as "The Pulverizer."
TCRI
episode S1.E17 march 2013While breaking into the hostile environment of TCRI headquarters, the Turtles discover the true intent of the Kraang and resolve to stop the alien invasion once and for all.
Cockroach Terminator
episode S1.E18 march 2013As the Turtles try to foil a Kraang invasion plot, they are hunted by a giant, indestructible cockroach.
Baxter's Gambit
episode S1.E19 april 2013Fed up with being humiliated by Fishface and Dogpound and defeated by the Turtles, Baxter Stockman seeks revenge by luring both parties into a deadly labyrinth.
Enemy of My Enemy
episode S1.E20 april 2013After witnessing the Kraang in action, Karai realizes the seriousness of the alien threat and approaches the Turtles to propose an alliance.
Karai's Vendetta
episode S1.E21 april 2013While the Turtles are infiltrating an undersea Kraang base, the Foot Clan attempts to capture April, forcing her to fend for herself in a battle of wits against Karai.
Pulverizer Returns!
episode S1.E22 may 2013When Shredder schemes to create a fearsome army of mutants, the Turtles have no choice but to rely on the help of the newest recruit to the Foot Clan: The Pulverizer!
Parasitica
episode S1.E23 july 2013After Leonardo, Raphael, and Donatello fall under the control of a parasitic Wasp, Michelangelo must fight his brothers to save them.
Operation: Break Out
episode S1.E24 july 2013Donatello breaks into a secret Kraang detention center in order to rescue Kirby O'Neil. But when he discovers they are trapped inside with a deadly mutant prisoner, he realizes that breaking in was the easy part.
Showdown: Part 1
episode S1.E25 august 2013As the Turtles make a desperate assault on TCRI to shut down an alien portal, they find themselves engaging in the most difficult battle yet.
Showdown: Part 2
episode S1.E26 august 2013As the Turtles make a desperate assault on TCRI to shut down an alien portal, they find themselves engaging in the most difficult battle yet.
The Mutation Situation
episode S2.E1 october 2013When Shredder teams with the Kraang to receive a batch of mutagen, the Turtles' problems only get worse--even putting their friendship with April at stake.
Invasion of the Squirrelanoids
episode S2.E2 october 2013While tracking mutagen, the Turtles bring a mutated squirrel back to the lair. When it starts multiplying, the Turtles must hunt the squirrel mutants and prevent them escaping into the city.
Follow the Leader
episode S2.E3 november 2013When the Turtles face Shredder's newest threat, an army of Robot Foot Soldiers, Karai captures Leonardo and forces him to do battle with these new and improved ninjas that can adapt to his every move.
Mutagen Man Unleashed
episode S2.E4 november 2013Donatello obsessively experiments with mutagen in a bid to find a cure for April's mutated father. Unfortunately this puts April in danger from a new threat--Mutagen Man!
Mikey Gets Shellacne
episode S2.E5 november 2013Michelangelo is tired of being the "runt of the litter." But when he fools around with some mutagen, he gets a dangerous infection that is mutating out of control.
Target: April O'Neil
episode S2.E6 november 2013April tries to resume a normal teenage life, but when Karai starts hunting her again, April realizes she may have put her new friend Casey Jones in danger as well.
Slash and Destroy
episode S2.E7 november 2013The Turtles find themselves being hunted by a new threat--another mutant turtle called Slash, who has a personal vendetta against the brothers.
The Good, the Bad and Casey Jones
episode S2.E8 february 2014After encountering mutants and ninjas, Casey Jones decides to take on "pure evil" alone. When he meets Raphael, the two hot-headed fighters must put their dislike for each other aside and work together against a common foe.
The Kraang Conspiracy
episode S2.E9 february 2014Feeling left out of the action, April insists on joining the Turtles on a mission to TCRI, where they learn a shocking secret about April's past.
Fungus Humungous
episode S2.E10 february 2014A fungus mutant spreading through the sewers causes the Turtles and April to experience their worst fears as Leonardo must face his greatest fear--losing his team.
Metalhead Rewired
episode S2.E11 february 2014When Donnie upgrades Metalhead's artificial intelligence, he must decide if he can trust a sentient Metalhead... or if he has created a new foe.
Of Rats and Men
episode S2.E12 march 2014The Rat King returns and tries to take control of Splinter again. Meanwhile, April leaves a cat with Mikey and he turns it into a mutant.
The Manhattan Project
episode S2.E13 march 2014Leonardo considers asking Splinter for help while facing Shredder's new assassin; Donnie must put aside his rivalry with Casey in order to uncover a Kraang plot.
Wormquake!
episode S2.E14 march 2014Facing Shredder's deadly new assassin, Leo must decide whether to risk his brother's lives or ask for Splinter's help. Donnie must put aside his rivalry with Casey in order to uncover a new Kraang plot.
Mazes & Mutants
episode S2.E15 april 2014When the Turtles play a fantasy LARP game to get their mind off of things, they must separate the difference between fantasy and reality.
The Lonely Mutation of Baxter Stockman
episode S2.E16 may 2014The Turtles create a retro-mutagen to help April's father;Stockman-Fly kidnaps April.
Newtralized!
episode S2.E17 may 2014Raphael is worried about Casey's ability to handle big mutant threats; Raphael and Casey cross the paths of Slash and his new partner.
The Wrath of Tiger Claw
episode S2.E19 june 2014When Tiger Claw returns, he vows to hunt and destroy the turtles. Meanwhile, Karai finds out the truth about her mother and real father, forcing her to make a life changing decision.
- Rise of the Turtles: Part 1
- Rise of the Turtles: Part 2
- Turtle Temper
- New Friend, Old Enemy
- I Think His Name Is Baxter Stockman
- Metalhead
- Monkey Brains
- Never Say Xever
- The Gauntlet
- Panic in the Sewers
- Mousers Attack!
- It Came from the Depths
- I, Monster
- New Girl in Town
- The Alien Agenda
- The Pulverizer
- TCRI
- Cockroach Terminator
- Baxter's Gambit
- Enemy of My Enemy
- Karai's Vendetta
- Pulverizer Returns!
- Parasitica
- Operation: Break Out
- Showdown: Part 1
- Showdown: Part 2
- The Mutation Situation
- Invasion of the Squirrelanoids
- Follow the Leader
- Mutagen Man Unleashed
- Mikey Gets Shellacne
- Target: April O'Neil
- Slash and Destroy
- The Good, the Bad and Casey Jones
- The Kraang Conspiracy
- Fungus Humungous
- Metalhead Rewired
- Of Rats and Men
- The Manhattan Project
- Wormquake!
- Mazes & Mutants
- The Lonely Mutation of Baxter Stockman
- Newtralized!
- The Wrath of Tiger Claw
Best moments5
- Fed up with being humiliated by Fishface and Dogpound and defeated by the Turtles, Baxter Stockman seeks revenge by luring both parties into a deadly labyrinth.
- When Splinter allows his teenage sons, the Mutant Ninja Turtles, to visit the surface for the first time, they discover that the surface world isn't as simple as it first appears.
- The Turtles must face off against a new enemy, The Rat King, who threatens not only to take control of the city, but Splinter's mind as well.
- Feeling left out of the action, April insists on joining the Turtles on a mission to TCRI, where they learn a shocking secret about April's past.
- After Leonardo, Raphael, and Donatello fall under the control of a parasitic Wasp, Michelangelo must fight his brothers to save them.
- Baxter's Gambit
- Rise of the Turtles: Part 1
- I, Monster
- The Kraang Conspiracy
- Parasitica