Leonardo is a lean mutant red-eared turtle with lime green skin, a golden mustard-yellow plastron, and a blue-green carapace with a bright teal design. He has black eyes, red markings over his eyes and the sides of his face, yellow marks on his upper arms and thighs, three fingers on each hand and two toes on each foot.
Leo wears a blue face mask over his eyes (with long tails down to his middle back), navy blue fingerless gloves (with blue trim) that extend nearly to his elbows and matching toeless socks that rise to mid-calf. He also wears a blue belt and strap over his right shoulder, with blue pouches on the belt and a Turtle emblem on the strap.
Leonardo is the wise guy. He’s charming and clever, and possesses a lighthearted quality that he often uses against potential enemies even as he fights them. He is prone to making jokes, sometimes at inappropriate times, and uttering one-liners which he believes "fire up the team". He can also be very arrogant, letting almost every win go to his head. He is shown to be the most attention seeking among his brothers.
Despite his carefree tendencies, Leonardo is capable of being both sensible and serious when the occasion demands it. When he does, as in the events of "Origami Tsunami", he uses both his charisma and his intelligence to sway his brothers into listening to him. He also knows when to step up and take charge. However, it is implied in that he may not be as confident as he appears outwardly. Such is in the episode "Minotaur Maze", where Leo doubts his mystic ability and fears that he's incapable of harnessing it properly, and also in "Portal Jacked!", where Leo's insecurities in his ability and losing his brothers are expressed. Leo is also shown to care of his brothers (and to some extent with Donnie).
Leo has been shown to be more rational and skeptical, denying the existence of things like ghosts and searching for a logical answer. He also seems to be the least naive out of his brothers, as they trusted Big Mama almost instantly, though Leonardo had his doubts on her background. Leonardo also seems to be the most exasperated by Raphael's antics, and lack of actual leadership skills. He can also be sympathetic towards other characters such as Bullhop.
Leo is known to be a compulsive liar as seen in "Flushed but Never Forgotten". He doesn't like being in trouble so he made his brothers promise not to tell Splinter about Piebald. Even willing to hurt Mikey if he tries to tell the truth to Splinter. Despite that, Leo is willing to sacrificed himself to save his family from Piebald.
Leonardo also demonstrates a talent in analytical thinking, letting his brothers and April deal with Shredder, while he and Splinter bargained with Big Mama. He cleverly planned ahead to defeat several powerful mutants, having fully expected Big Mama to double cross him in some way, surprising even Splinter himself in Many Unhappy Returns.
Like his brothers, Leonardo began his life as a baby turtle in Baron Draxum's laboratory. Wishing to make mutant soldiers, the Baron used Lou Jitsu's DNA to mutate Leonardo into an anthropomorphic Turtle. He was taken from the lab by Lou Jitsu, along with his brothers.
A red-eared slider turtle, Leonardo is quick-witted and intelligent. He uses his sharp skills to beat opponents and find shortcuts around obstacles. And he always knows the perfect time to land one of his many one-liners!
- Kenjutsu: Leonardo is a highly skilled martial artist and master swordsman. Leonardo was trained by Splinter in Japanese sword fighting. In beginning of the seires, Leo wielded his traditional twin katana in battle, but they were broke in his first fight against Baron Draxum's Guardsmen. His skills later translated into the use of his newly acquired mystic ōdachi. He makes use of his ōdachi for skilled offense and defense, allowing him to slice through sturdy material, and enabling him to fight against powerful figures such as the Guardsmen, the Foot Brute, and Baron Draxum.
- Ninjutsu: Being raised by Splinter, Leonardo, like the rest of his brother, is skilled in the ways of ninjutsu.
- Stealth: As a practitioner of ninjutsu, Leonardo can slip and out of areas undetected.
- Ninja Mind Meld:
- Portal Creation: Via his ōdachi sword, Leo can cut holes in space, allowing him to transport almost anything. Leo had trouble controlling the power of his sword when he first acquired it, often opening portals by accidents or creating ones too small to use. However, as he continued battle villainous mutants and the Foot Clan, he became more adept in using the sword's power.
- Strength: Leonardo is the second physically strongest of the turtles. Thanks to his mutation Leonardo possesses strength greater than most humans.
- Speed: Leonardo possesses remarkable speed. His quickness and agility make him able to avoid and counter enemy attacks. Leo can also move in quick bursts of speed faster than the eye can follow. He also uses his immense speed for his swordsmanship to deliver super fast strikes. It is a possibility that he is the fastest of the four turtles.
- Cooking: It is hinted in "You Got Served" that he can also cook but it is shown that he sometimes burned the food when under pressure or it is the right amount of heat that he made from.
- Tactician: In the episode "Air Turtle", he apologized to his brothers about how bad a brother he is to them and he initiated a plan on how to defeat the New York Daves in basketball, this shows how he is capable of learning about his brothers strengths and weaknesses as well as he knows how Donnie is bad at shooting.
- Raphael: Raph and Leo are sometimes butting heads, whether it is over wrestling or Raph's leadership.
- Donatello: Despite them being the middle brothers, Leo and Donnie don't get along well, with Donnie hating Leo's puns (even trying to get rid of them in "Donnie's Gifts") and crazy schemes, and Leo thinking Don needs to loosen up. They do love each other, though, and will always have each others' back.
- Michelangelo: Leo cares deeply about Mikey. Though he will get annoyed by Mikey's competitive side and will participate if pushed too far.
- Splinter: Leo seems to be the one who most often gets on Splinter's bad side, leading him to constantly smack Leo in the head with his tail.
- Baron Draxum:
- Meat Sweats:
- Warren Stone: Leo is unsure who he is, but sliced him in half due to panic.
- Foot Clan:
- Big Mama: Leo was the only one of the brothers to intuit that Big Mama was actually evil.
- Ghostbear: Leo accidentally defeated Ghostbear and broke his undefeated streak.
- Captain Piel:
- "Dude, you gotta make it to rehearsal." - After Donatello's failed masquerade.
- "Soooo... You guys from Jersey?" - When faced with the just-transformed Jogger Guys.
- "You had to ruin Cannonball Day." - Before his Katanas were destroyed.
- "Get- me- off- this- ride!" - Falling into the portal created by his sword.
- "You'd think as a birthday bot- you'd be a little more chill at a birthday party." - While fighting Albearto
- "And who doesn't love my one-liners- they fire up the team, right guys?" - During Donnie's Gifts.
- "Okay which one of you made Raph angry?" - Shell in a Cell
- "¡Vamonos, hermanos!" - Hot Soup: The Game
- "Why do we always have to dress up as grandmas, Donnie?" - Operation: Normal
- "Time to go to obedience school."- Mascot Melee
- Unlike previous incarnations, this version of Leonardo is the rebel and self-proclaimed coolest turtle, instead of Raphael, rather than his normal role as leader of the team.
- Since he isn't the leader, Leo is more laid-back and less responsible than his past incarnations.
- Leo also isn't the oldest turtle in this incarnation, in previous incarnations he is. Instead, he is now the middle and second youngest after Donatello.
- Since this version of Leonardo is a red-eared slider turtle, he sports visual marks (red stripes over his eyes and yellow stripes over his arms and legs) which are common and give this species its name.
- While he is taller than Mikey, real red-eared sliders are actually smaller than box turtles.
- He is constantly creating catchphrases for the group to use.
- Leonardo has a protective relationship with Michelangelo and takes him under his wing.
- According to a behind the scenes video, Leo is confirmed to have the smarts to be the leader, but seemingly lacks the maturity as he is more interested in enjoying life as a teenager.
- It is possible that this could foreshadow one of the major changes hinted prior to the series' premiere.
- Leo is the second turtle to be seen without his mask.
- A running gag with Leo is that he is constantly seen dabbing.
- Leo seems to have an interest in basketball as seen in "Hypno! Part Deux" and "Late Fee". This is confirmed in "Air Turtle".
- Leo knows some Spanish.
- Señor Hueso's nickname for Leo, "Pepino", means "cucumber" in Spanish.
- Leo have been shown to cook as seen in "Bullhop" and "You Got Served".
- As shown in "Lair Games", Leo has been the lair games champion 5 times in a row.
- As shown in "The Clothes Don't Make the Turtle", Leo seems to have an interest in magic performed by magicians.
- Leonardo (Rise of the TMNT)/Gallery
- Leonardo Splinterson (Rise of the TMNT)/Animations
- Leonardo Splinterson (Rise of the TMNT)/Appearances