Of course not, they're mutants. Duh!

That's what I thought, but there is another wikia that claims they are half human. These versions, and while I don't agree with that, I'm reluctant to edit that out.

Where have you been for last four years?!

Here. and they just changed it back to normal in that wiki. Plus I have some of the DVDS and in those the turtles are described as being half human as well, which I discount

Here's a link to what one user is using to make some rather ridiculous claims. http://turtlepedia.wikia.com/wiki/Thread:15445#37

They are half-human half-turtle mutants. Hence the reason they are build like a human, but share turtle characteristics like green skin, a shell, and the way their face is shaped.

Just like Master Splinter is a half-human half-rat mutant

No they are NOT half human, the mutagen turned them humanoid, because that what mutagen can do/does. Master splinter is half human half rat because he was human to begin with.