Alrighty, so, for lack of a better name, this is Korra's back apron. I have been affectionately referring to it as the ass cape... but I felt that a more appropriate name was in order. XD
If ya'll be interested, here is a brief tutorial:
1. You are going to want to make a paper pattern before you cut anything out of leather.
2. Measure around your waist (or your hips, wherever you want it to tie around you. I measured around my hips because that seems to be where Korra likes to wear it) to see how wide you want your back apron.
3. Measure from your waist or your hips down to just above the tops of the back of your knees. This tells you the measurement of the tip of the apron.
4. In the front, measure down to your mid-thigh. This tells you how far it goes down in the front before it needs to taper to the lowest point in the back.
5. Make sure to leave a seam allowance as you make the pattern. For seam allowance on the waist, I added an extra 3 inches so I could thread the tie around the waist.
6. Sew the seam at the top for the tie.
7. Sew on the fur. If you choose to use lamb skin like I did, you don't need to prepunch the holes into the leather because lambskin is soft enough to simply use the leather needle to make the hole.
-Remember that adding the fur trim to the bottom will add length to your apron. With lamb skin, the fur hangs down about an inch from where you cut the leather.
-I made the tie out of left over pant fabric.
Hope this helps. Happy Korra cosplaying!