Attached Link: http://www.gimp.org/

"Poser is a 3D graphics program specializing in working with human figures." Important to emphasise that you can't actually *make* 3D models in Poser (in case you were thinking you might want to do that), only work with ready-made ones. You might also want to have a look at some of the work in the fractal gallery. Most of these are made with free, downloadable programs, but you'd likely need additional image-manipulation software; check out The Gimp (see link) for a good free one.