Nah, you right about the head being too large. If I had another week I'd probably shift it somewhat. (Or maybe not? I really love the shape of the negative space between the hat and the horse's head.)

The horse's expression :0

Awesome job. The head is a little small compared to lil nas but great work

This is cool and it has a bit of a horseman of the apocalypse vibe to it (that MtG horse is pretty intense looking so that might be why).

I love the horse's expression and the stylized look it has. The muscles in the neck are really impressive. Lil Nas X's pose is great and dynamic too, especially with the extreme perspective.

The only thing is that the horse's head looks quite small to me, although I can see it'd be a struggle to make it larger within the challenge limits while keeping all the other things I love about this.

You've got my vote, anyway!