Artist’s comment from DA:

As some of you might know, I have been creating and posting mlp anatomy guilds and head cannons as patreon rewards for over a year now. This was one of the early ones, back in February of last year.

There are more of these, plus a variety of extra content, available for my patrons. I have full charts like this available for pegasi, earth ponies, unicorns, and alicorns, showing skeletal structure, muscles, and a variety of other things. If you are interested, or want to support me, even if it’s as little as a dollar per month, then go take a look at my page!