(http://1.bp.blogspot.com/_LtwkN4oRTe0/S2HuhAXxdxI/AAAAAAAABzU/v5as05t1-vg/s320/thegimp.png)
Not exactly an edit, nor pixel art, but I wanted to see what your tree would look like with larger roots that would look like arms crossed and the tree having his "head" in the middle, as if frowning and being of some bad mood. I didn't quite manage to do it (he more looks like an ill-manerred frog-tree), but since the pix is now online, I thought you might want to get an eye and possibly refine your character's design.