Perspectives can do a lot to pics, but I remember when I was in high school there was a bait store we used to goto when fishing and there was an old picture of a guy that killed a 15ft rattle snake. There were no odd positions or angles of the picture it was a guy holding the dead snake over his arms and the head and tail were both touching the ground.

He found it in his cabin outside Comanche, TX and shot it. So they are definitely out there. That snake in the pic doesn't look 15 ft though.