Thank you! Hehe, I always thought that was one of the things that made them interesting. There aren't many other fantasy creatures that I know of who have two rib-cages. That and there is a variety of ways you can interpret a centaur. I was thinking of doodling a reptilian-themed one just for the fun of it.
Thank you! I think the second one has wrong perspective though; there should be less of it viewable from the side of his head because of the way his face is tilted. I'll get around to fixing it though, eventually hehe.