This page shows various creature concept art studies, click the images to open a larger version. Below shows the final orthographic projections and right shows the final CGI creature model as it appears in the film.

Rock creature concept art series 1 Rock creature concept art series 2 Rock creature concept art series 3 Rock creature development from chosen concept art Rock monster movement study Rock monster final design Orthographic drawings of the final rock creature The final rock monster, rendered in Mental Ray for Maya as it appears in the film