This is a model of a Thwomp that is made especially with molding him in silicone rubber in mind. This will allow you to make cement castings from the mold!
He has gone thru several iterations adding draft angles and bevels to some problem areas.
See the following video to see the end result!
Cement Thwomp Build Video
Finishing the model with SmoothOn XTC-3D definitely helped reduce the print lines for casting.