Test your 3D printer's limits with this hard-to-print test object

Theoretically, 3D printing technology can be used to make just about anything. Even a basic desktop FDM 3D printer should be capable of creating diverse, complex and unnatural shapes, just about anything you can imagine. The reality is that most users only 3D print basic geometric shapes. So...
Test your 3D printer's limits with this hard-to-print test object