Speed of an animation is usually done through what you use to upload/make it. What did you use to actually animate it? Typically, Graphics Gale and similar programs are good for that.
Just looking at the base sprite, you could probably clean it up a bit. Stuff like the gold bits at the face and the steel at the chest don't read particularly well as actual metal. The chest utilizes something called "Pillow shading," which you should probably look up so you don't continue to use it. You've also shaded several things, but left the main body completely blank. If the legs have shades, you should the blue bits done as well, not just the feather imprints.
Overall, the shape of the bird is pretty well done, and the legs themselves actually look really good by themselves. The knight could use a bit more reference, like people riding horses and armor. It's a bit hard to read him as having individual parts because of the armor, and the helmet looks a bit all over the place.
As for the actual animation, the legs are easily the best part. Another frame wouldn't hurt, but everything that isn't black or below is incredibly stiff. Assuming it's running at a decent pace, the body and the knight should constantly bounce and move following the direction of where the legs take it. I'd recommend looking at walk cycles for things like chickens and even raptors to get a sense of how the body would move, and maybe Final Fantasy's Chocobos if there's any for them.
Final, there's a button to edit your posts, so you don't have to make two separate ones for future reference.