Lil fox - pixel

I thought I'd try this pixel art thing again after getting immensely bored doing revision. He's kinda cute, but I'm not entirely happy with the animation.

So yeah, critique seriously encouraged, I know very little about pixel art and would love to know where I'm going wrong. Help me out?

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Edit:
This seems to be quite a common question so I'll address it here.
You are welcome to use this particular piece as an avatar on DA, forums, etc, provided you credit me for it. Please leave a comment letting me though, it's always nice to know that someone wants to use this one and it makes it easier to keep tabs on my work.

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Another edit:
It seems this need to be clarified, so I'll try again.
You may:
Use this piece as an avatar on DA or other forums, if and only if you give me credit, and link back to either here or my gallery.
You may not:
Upload this piece to anywhere and claim it as your own artwork.
Use this piece in any way, shape or form without crediting me.