Quoting AA (Noname)
You need bigger heads. The 1x1 plates barely looks like a head. I also don't think the black parts fit here well. Apart from that, very good
When I was building him I tried a bigger head and it looked really bad, he looks much better with the smaller head in my opinion.
Also I know the black doesn't fit, but that was the only color I had those parts in at the time I built him.