PREPARE cake mix batter according to package directions; add Nerds to batter. Bake according to directions for 24 cupcakes. Cool completely. Frost cupcakes, using a little more frosting than usual on top ("tombstones" will be pushed into frosting).
WRITE spooky words such as "RIP" or "BOO" on Crunch bars using decorator icing. Let sit for a few minutes to dry.
PRESS Crunch bars into cupcakes to create "tombstones." Creatively place Skulls N' Bones next to "tombstones."