Scary, but not TOO scary

This is a sketch from an early reader I'm doing called "The Bad Witch." The tricky thing is to make a witch who looks bad, but not too scary for the little guys. My mother ran a preschool/day care center for many years, and I used to work there from time to time. Once, around Halloween, I was playing a game with a 4 year old boy. He sat across the table from me and drew a bunch of pumpkin shapes. Then he told me what kind of jack-o-lantern face to make in each one (silly, sleepy, etc.) Finally, he told me to make a scary face, and I did, but when I turned it around to show him, he about fell off his chair, he was so scared! I felt terrible. Now I'm a little leery of using my scary drawing powers on little kids.