Sorry, but I do not see why printable 3D models would be more complicated than classical others ??
Most of my models are printable, simply rescale them to an acceptable size for a 3D printer, and convert to STL ..
here some example (with the photo of the printed model)
https://www.cgtrader.com/3d-models/animals/reptile/cartoon-gecko-rigged
https://www.cgtrader.com/3d-models/animals/fish-aquatic/cartoon-dolphin-rigged
https://www.cgtrader.com/3d-models/character-people/fantasy/colorful-cartoon-monkey-rigged