This isn't that bad. The form, and anatomy of everything in this is put together rather well. One thing that really throws it off though is the coloring materials you used. From what it seems, you might have used some cheaper supplies or didn't really wish to push too hard on the color. For this, I'd recommend that you get some Prismacolor colored pencils. Although they may be a bit more expensive, ($13 being the cheapest I've seen), they're entirely worth it. They have strong pigments, amazing blending, and can make an image really vibrant.
Personally, I prefer doing base coloring in crayola, along with the first few layers of shading, then for the darker or more outstanding areas, I use my Prismacolors to really make the image "pop".
That's about all I have to say is get some better colors, because honestly, at first, due to the lightness of the image, I didn't really know what this was of. Once I read your description, I noticed the accuracy to the anatomy and overall form, but the light coloring of this really threw me off,
Hope that this helps! Your work is truly astonishing, and if you use the right type of materials, it'll be even better!
I like it great job
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