In a microwave, melt chocolate chips; stir until smooth. For tails, use a dab of chocolate to attach five candy corns to the chocolate side of half of the cookies in a fan shape; refrigerate until set.
In a large saucepan, melt butter. Add marshmallows; stir over low heat until melted. Stir in cereal. Cool for 10 minutes. With buttered hands, form cereal mixture into 1-1/2-in. balls.
Remelt chocolate if necessary. Using chocolate, attach the cereal balls to the chocolate side of the remaining cookies. Position tails perpendicular to the base cookies; attach with chocolate. Refrigerate until set.
For feet, cut off white tips from 52 candy corns; discard tips. Attach feet to base cookies with chocolate. Attach one candy corn to each cereal ball for heads.
With a toothpick dipped in chocolate, attach two confetti sprinkles to each head. Using chocolate, dot each sprinkle to make pupils. Let stand until set. Store in an airtight container.