End of Week 1 - Changeling

So, I've been working on drawings here and there, trying to get more comfortable with drawing ponies - when someone comes to me with a challenge.

"Draw a changeling. It is based around the MLP FiM base form and if you can figure out the shapes necessary from a reference of the core form (like say Rainbow Dash) then you can sketch a changeling. Try not to use a changeling ref except for the eyes and ears. I wanna see if you know how to really use a reference."

Well, considering I've spent my last few days working on drawing ponies in my free time (not to mention getting a bit of practice in when I'm on break at work) this seemed like an easy enough challenge, and a nice deviation from the norm.

So, reviewing back with the person who issued the challenge, one of the most prominent issues (and one that I've been noticing with all my drawings) is that they always seem to come out blocky, and I still have a few proportion and anatomy hiccups that need to be worked on.

So - what do you guys think? Anything else that could be improved upon with this drawing? Let me know, down in the comments!