Providing the original picture is quite easy, he's not providing it because he doesn't have it (in other words it isn't his picture). It's impossible to be conclusive based on the resolution of the pictures provided, but that's by design! It would be quite easy to tell the picture had been faked in a high-resolution format.
Based on what we're provided we can still deduce it's probably faked for a couple of reasons:
- The heads look very similar if not identical, all point in the same direction and have the same general angle w.r.t. the camera.
- The hoods seamlessly trasition into the body, are all flattened by the same amount, and have the same coloring patterns.
- The picture has an icon in the lower right, apparently an eye with a magnifying glass in front of it. Logo denoting this came from a modified picture website?
- The scales on the "chin" of each head are sharply distinguished, and the scales on the body are sharply distinguished, but in the region where the heads meet, they are blurred.
Unless this picture can be provided in raw form from the camera, it's undoubtedly a fake. Just do a search for "3 headed snake" on google and you'll find hundreds of pictures all made in this same fashion (and all fake).