High poly Gray Spiky Modular Rock 230715 (Polygon mesh 3D model) is available on CGTrader for $39. Original author: mega-3d. Specs: 1500000 polys, 750000 verts.
OBJ (OBJ, filesize: 2.2 GB), FBX (Autodesk FBX, filesize: 2.2 GB), TEXTURES (Textures, filesize: 2.2 GB), SPP (Substance Painter, filesize: 3.42 GB)