I'm not a fan of the random dark pixels you have scattered across padding. I take it you were trying to show wrinkles on a sheet, but the contrast is so high and the lines are so scattered and without the feeling of intentional placement that they feel like dirt or something spotty on the cloth rather than the form you were going for.
The bottom legs bother me a bit as well. You've doubled up the black line on the legs which stands out in a really strong way contrasted with the rest of the sprite. The diagonal bars are already thicker than the bars above, causing those lower portions to feel quite thicker than the top half.