Looks like the turtle in sly racoon :D

same as how I would imagine him to be. he was an engineer. Now the big challenge is Leonardo. Raph, mikey, and Don are easy since there are people in real life that are like them when they were teens as well. Leo is very interesting, I will be surprised to see what you come up with. I have my own ideas, but I would like to see yours first before I share. mostly because I don't want to influence your artistic ideas and what you draw inspiration from

Loved the background and color choice, but the eyes don't make me think of the gentle creature the turtle is. Other than that, good work.