This is courtesy of amyo on the OpenSCAD forums. It is a representation of a primate brain from MRI scans. This STL has been cleaned and is manifold, and usable as an import() to OpenSCAD. It is a LARGE STL. Also inclused are two negative halves intended to form a mold. These may print best if rotated, depending on the capability of your printer. I have not printed this. Update: Added the brain split into two halves for printing. Probably needs support.