This is a remix of the dragon head from the excellent Tower of Mystique dice tower. The original is 185Mb, this is about 10% of that file size without losing detail. I imported the original into MeshLab, removed duplicate faces and vertices, and then ran Quadric Edge Collapse Decimation. That took it from 2.29 million vertices and 765K faces to 191K vertices and 382K faces. I haven't tried reducing it even further but I'd bet you could reduce the file size even more without losing detail.