Do you want to do 3D animation or 2D? For games or for animated films/TV shows?
Generally speaking, if you want to do 3D animation, the most important thing you can have in your portfolio is actual 3D animation. There are so many free resources such as rigged characters you can download off the web to animate with, and also many free/cheap 3D animation software, as well as online tutorials that you can pretty much teach yourself. But since you want to go to school for it, then show animation in your portfolio.
If you want to do 2D animation, or the 3D animation program requires you to show 2D skills, then try to target your 2D portfolio to the kind of drawings and paintings that animators would usually do, such as gesture studies of poses, facial expressions, anatomy/figure studies, life drawing, portraits, animal sketches, animal anatomy/figure studies, animal poses/expressions, character designs, etc.
You can also do 2D animation too on your own–there are excellent and affordable 2D animation software available that will give you the same features that professional 2D animators working on TV shows would use.
What you currently have, seems to be on the right track in terms of content, and it’s mainly the quality that needs improvement. Be more accurate in your forms, your values, and push for more clarity in your forms. Some of your drawings are too flat with similar values and not enough dynamic range. Make sure you get the middle tones, the highlights, and the shadows right. There should be at least three distinct value levels of middle, very light, and very dark in the average drawing, and then if you add one distinct value between the three, you should be getting at least 5 distinct values that are clearly readable. Five is a great number to keep in mind for the basic management of your values.
