There are no spells that will transform your physical form.
You cannot change your DNA, neither by magick or any of its spells. That being said, you are a human and a human you will remain! A human, with two human eyes, ears and a normal human body structure. You cannot bring any change to it.
Magick is spiritual. It is working with the energies of the universe. It abides by the laws of the universe and has its limitations and it does not cross the boundary of reality.
So don't waste your time on such fictional, unrealistic spells. It is surprising that people expect so much from magick.