Hey there,
this one was more work then i expected, but im satisfied with the result. You can print him as whole with FullGyarados or GyaradosWithBase. You can print him in parts too, with Tail, Head and Middle for the full gyarados or GyaradosForBase and Base for the Base Version.There is also a HalfGyaraos, if you want to use him with your own bases.