For the first sprite, I wouldn't use the outline color for his eyebrows. Also, his head is the size of a child's, and it doesn't really fit with Ross' body.
For the second sprite, the custom stuff looks really pillow-shaded. Also, the mask is still almost the same color as the hair, so maybe make it a bit brighter? Or cover the mouth altogether.
Otherwise, these aren't bad. Keep up the good work!