Nice work Jorik, and welcome to Blender!
The shape is pretty readable - I think I would have first guessed it’s a tiger, or other big cat, despite being low-poly or somewhat abstract (even without the title giving it away). The texturing looks good, and reminds me of concrete or some kind of rock.
But there’s something about the shading that makes it look more like an unfinished gem-like material (a bit dirty or rough). It seems to have too much reflectance, transparency or translucency. Hard to tell, though.
You might want to tweak the material settings and/or lighting setup to get something that is more obviously concrete.