I had the opportunity to print a dinosaur at work ( www.3dphacktory.com ) on the Objet 500, so I remixed IcanCwhatUsay's Tyrannosaurus rex to be larger and use multiple materials. :)
Because of the way that the original was created, it was easy to isolate the eyes and teeth in Netfabb Studio and move them into separate files.
In Objet Studio, I imported the three files together as an assembly, and chose a different digital material for each one.
Download the three STL files: body, eyes, and teeth
Start a new tray in Objet Studio
Insert the three STL files as an assembly
Choose different materials for each part in the assembly
NOTE: I used Shore50 on the body, and it made the legs just a little too rubbery for the dinosaur to stand without leaning back on its tail, so I recommend using something more rigid.