The Child Snatcher
If you have seen Chitty Chitty Bang Bang, you know that this evil villain is the creepiest guy in town.
What you need to to: Create a black top hat with construction paper and scotch tape by making a cylinder with two pieces of paper and a circular brim with a third piece. Create a big, fake nose with tan construction paper and string or moulding clay that can be glued to your face (with makeup glue, of course). Wear a long trench coat to complete your look.