Well, since you became a Brony was inevitable that your next works were related to My Little Pony Friendship is Magic .
Ok, let's begin:
Overall I think the design is very original though not a very common practice coming from you to do oc, so I must clap this initiative. Well done pal .
I especially liked the fact that I did not follow you completely the same drawing style used in the series, and instead you decided to create his own style, something that is actually very good because it generally people keep the same style and decides not innovate in this area or worse just take a picture in the series, will change the color to one of the characters or are put on a hat or something and voila, new character xD.
Esthetically it looks very nice, especially the expression and coloring, quite realistic as you always do in your work . However I think you could improve him a few things, mainly the tail. Something you could to the tail would look more lush is putt soe few small hairs protruding from larger hairs to increase the effect and make it look even more realistic.
But hey, that's just a personal observation , so I have no more to say keep up the good work
See ya pal!!