Leonardo

Leo is the class clown, a charismatic teenager who's constantly cracking jokes, making sarcastic remarks, and puns, even in dangerous situations. He uses humor as his primary communication tool and often to cope with stress or pressure.

2. Charming, Arrogant, and Confident
   He has sky-high self-esteem (sometimes bordering on egomania). He sees himself as the coolest, most handsome, and most talented brother. He loves being the center of attention, striking dramatic poses, and acting like he has everything under control, which often irritates his brothers, especially Donnie and Raph.

3. The "Unexpected Leader" and Hidden Strategist
   At the beginning of the series, Raph is the team leader, which allows Leo to be completely free of responsibility. However, behind his carefree facade, Leo possesses a brilliant tactical mind. He has great intuition, is very good at reading people, and is capable of devising clever, impromptu plans in milliseconds. His leadership style is not based on honor or rules, but on cunning and knowing how to leverage his brothers' abilities.

4. Lazy but Talented
   He's the classic character with incredible natural talent who prefers to avoid effort if he can. He'd rather find the easiest or quickest way to solve a problem (which perfectly aligns with his sword Ōodachi's portal powers) than spend hours training.

5. Immature, but with a Big Heart
   Although he often acts selfishly, immaturely, or competitively to inflate his own ego, his loyalty to his family is absolute. When things get really serious and his siblings are in danger, Leo is able to swallow his pride, mature suddenly, and sacrifice himself for them—an evolution that is fully realized in the series' movie.

The design follows the overall aesthetic of the show: a style heavily influenced by anime, with kinetic lines, sharp shapes, and highly saturated neon colors.
Gestures: As seen in the image you shared, Leo is extremely expressive. He often has a lopsided, mischievous, or mocking smile, very mobile eyebrows that protrude from his mask, and a gaze that radiates self-confidence and sarcasm.

It retains its characteristic blue color, but the mask's ribbons are extremely long, floating very dynamically when it moves or fights.
Combat gear: He wears a blue harness that crosses his chest diagonally to hold his weapon. He also wears long wristbands and dark blue/light blue ankle guards, as well as a belt with a circular emblem.
The Shell: Its plastron (the chest of the shell) is flat and segmented into angular geometric shapes that match the overall aesthetic of the series.

Unlike previous versions where all the brothers looked like the same species of turtle, here Leo is specifically a red-eared slider turtle.
Distinguishing features: It has two bright red or deep pink stripes above its eyes, right at its temples, and lime green skin, mimicking the actual markings of its species. It also has some yellow markings on its shoulders and thighs.
Physical build: It is remarkably tall, slender, and of athletic and lean build. Its design uses very angular lines, which accentuate its agility and speed over brute strength. It has three fingers on both hands and feet, and a dark green shell with blue markings.

Father: Splinter
Brothers: Donatello, Raphael, Michelangelo
Friends: April, Casey, and Karai