$15 Raw Pig Liver Low-poly 3D model by realityscanning. Available on CGTrader with 50000 polys and 50000 vertices. Check it out on CGHub.
STL (Stereolithography, filesize: 19.8 MB), OBJ (OBJ, filesize: 34.7 MB), TEXTURES (Textures, filesize: 78.4 MB), PLY (Ply, filesize: 7.67 MB), FBX (Autodesk FBX, filesize: 22.4 MB)