Main is fairly similar to Mike’s, but face have a different shape and I made the ears more pointy + added eyes 
The eyes are at the wrong spot. Gives this feeling, in the smooth version, of a dog.
A predator has his eyes pointing forwards (focus on object).
While a prey, has eyes at the side, scanning the surrounding for predators.
Good comment. Couldn’t put my eyes (pun intended) on what was off there 
I know that feeling. … things nagging in your head …
Yeah… and there is something also donkey-ish in the shape of the head…
edit: maybe the ears (?)
It’s difficult to use a few vertices and still keep a recognizable figure.
But every body, doing this chessboard lesson, have this difficulty.
Including me. But try your best and move om.
It’s just a process of experience, skills and knowledge.
Which is a factor of spend time.
Good Knight.
Last one is getting more horse like. The pinching of the nose so the muzzle is relatively wider is good. The eyes better placed but seem vertically oval rather than more horizontally if anything.
You can tweak for ever though, but its not a real horse.
Ok, enough tweaking. I think it resembles a horse reasonably now (and it’s not a real horse as @NP5 pointed out… it’s a chess piece). Here are my 3 versions of a knight piece: low poly, medium poly and high poly with different design:










