Measure the cereal into a large bowl.
Pour the gelatin in the bowl with the cereal and mix.
Melt the butter and marshmallows in a large sauce pan.
Add the dry ingredients to the melted marshmallows.
Mix vigorously until well combined.
Rub butter on hands, and working quickly, roll the cereal and marshmallow mixture into balls. Work from the outside edges toward the middle. This step must be completed while the mixture is still warm. Squash the balls slightly to create a more pumpkin look.
Place one candy pumpkin on top of each pumpkin.
If not eating soon, wrap each completed pumpkin in wax paper and secure with masking tape.