The red bits look totally out of place. They don't really even look like they fit properly on the head. Unless I'm just blind, they look like they're all for the most part the exact same shade of red with almost no variation.
I'd recommend being a bit more liberal with shading those to keep it consistent with the rest of the head.
You can do much better turtle whole head looks pretty rushed.
Try to redo red parts and teeth look bad mirrored imo.
Ears shading looks bit weird to me.
Try to make back more intresting.
You need to do some shading on the red parts or they don`t look like they are part of the texture. This looks like a female demon mixed with a little bit of cat.
Klein Bottles only have one surface so they are the easiest thing to clean