1. Cut off the top of the pumpkin. Scoop out the insides. Discard the lid.
2. Use a chisel to outline the warlock's eyes, nose, and mouth. Enlarge and deepen the initial carving until the desired look is achieved. Chisel wavy hair that comes down from the top of the head.
3. Cut circular pupils in the center of the warlock's eyes. Insert a marble into each hole.
4. Cut an 8-inch wide strip of screen off the 2-yard length. Set it aside to use for the brim of the hat. Fold the remaining screen in half and then roll it into a cone.
5. Adjust the width of the base of the cone so it will fit on the warlock's pumpkin head. Staple the overlapped edges together at the top and bottom of the cone. Fold down the top point of the hat and staple it in place.
6. Fold the width of the eight inch strip in half and staple it to around the base of the cone, gathering it together whenever necessary. Trim off any extra brim. Tie a ribbon around the brim to make a hatband.