i just wanted to show him at certain stages in his life.
left to right, there's the 5 year old Leon. he is the greenest he will ever be, and his red markings are short and stubby, just as the baby turtle himself. the blue markings on his shell are looking like donuts at this moment, there are no spiky edges to them. they're just squarish looking circles. this leo, he prefers wearing his bandana on his neck. very adventurous and outspoken little guy, and so very troublesome for his poor single dad.
second is 16 year old Leo, fresh after the Kraang invasion. his red markings have gotten longer by now, his scales have gotten a bit more yellowish, but he's still very green. his personality doesn't need introduction, the only thing that's different is maybe that now he's more humble, after the Kraang incident in which, well, he almost sacrificed himself for the world.
and last, is 40 year old Leonardo from the Kraang Apocalypse timeline. he is barely in his 40s, looks older than that, wonder why that is. he looks much more angular but also sturdy now, and is much stronger. the red markings are even longer, their top parts meeting in the middle of his head, bottom parts connecting to the jaw and then going down his sides. shell is scratched in many places, the markings on it now are all angular and sharp, there's nothing soft about them. his personality hasn't changed much though, he is still the same constantly-joking Leo, just now he has more responsibilities, and after Splinter's passing, has to be the head of both his family, and the resistance, he's now a pillar of strength for everyone around him. he needs a break tbh