This time I was asked to make it a little bloody, so instead of modeling him after the moon I modeled him after the stars and cut star shapes in him. I also had the idea to make him "moon blinked" like in Guardians of Ga'Hoole... like, in a trance from staring at the moon for so long. So that's why he's got that empty look.
I love Guardians of Ga'hoole. The blank stare and tilted head make him seem childish. The blood from his eyes makes it look like he's crying. The effect is a creature that you just want to love, care for, and keep from harm forever.
Well he's really just a ponified version of my fursona Kaloyan who is a wolf with horns and bat wings just because I thought it looked cool. The official explanation for Starmoon's look is that he's a normal pony who was twisted by Discord's magic.