Donnie is a super intelligent, cynical, narcissistic, autistic nerd and Leo is the hyperactive, ADHD, annoying, kind, "funny" medic. Their relationship is a love hate one. They love each other, and are the closest out of the four. Donnie only let's Leo touch his soft shell. Donnie is a soft shell turtle and Leo is a red eared slider. They're turtle mutants. Their other brothers are Raph, the oldest, and Mikey, the youngest. The twins are both 17 years old.