First, arrange 9 cupcakes into a 3 by 3 grid for Frankenstein's face and then place 2 cupcakes on the bottom for his neck.
Then, cover the entire cake with green frosting. Squeeze the cupcakes together as best as you can and continue to push them together when frosting. They will tend to spread out as you add the frosting so give them a little push back to get them back where you would like them.
Begin decorating the cake by adding frosting hair, candy eyes, Twizzler eyebrows, the Oreo nose, candy corn teeth, and additional frosting stitches and scars.
SubstitutionsThe orange Twizzlers were leftover from the Harry Potter spider cupcakes but you could easily substitute orange frosting or the classic red Twizzlers instead so those would be easier to find.I found the Brach's green candy corns at my local JoAnn's but again you could swap those out for the traditional orange ones.If you would like you could use black sprinkles for the hair instead of frosting. Then the frosting and the stitches would be more distinct. Note: the candy will quickly get soggy on the cake so it is best eaten on the first day. If you do keep it till the next day, remove the candy before eating.