Ok, so basically, the SpeedWing is built for speed, agility, and endurance. 

Its head is very aerodynamic, and the ruff just looks good, OK? Instead of spikes on its back, there are leathery flaps that can open and close to become more aerodynamic. (Kinda like Toothless in How to Train Your Dragon) As you can see, it also has flaps on its legs of the same material as the "spikes". These flaps allow for faster and smoother turning. They can also be collapsed to become smaller. On its chest, it has a fin thingy that helps it slow down and turn. Its wings are pretty normal, similar to SkyWing's. It has little glider things on the end of its tail that hep it glide.