Check out Futuristic War-Robot with Jetpack Low-poly 3D model on CGTrader for $45. High-quality mesh by samsuel: 19428 vertices. Rigged.
STL (Stereolithography, filesize: 459 KB), OBJ (OBJ, filesize: 545 KB), ABC (Alembic, filesize: 478 KB), DAE (Collada, filesize: 370 KB), FBX (Autodesk FBX, filesize: 263 KB), 3DS (3D Studio, filesize: 201 KB)