Spread a layer of green icing on top of each brownie.
Using the black decorating icing and a round tip, add hair to your Frankenstein brownie. Just do a zig-zag along the hairline, and outline around the top of the head. Then fill in with the icing.
Add candy eyeballs for his eyes.
Add a small smile or mouth with the black icing.
Then add a small piece of stitching to one cheek, also with the black icing.
And that's it! They're ready to serve.
Video
Notes
*I used Wilton Leaf Green and Black icing colors for my Frankenstein.*If you don't want to buy icing, you can make homemade cookie frosting; then just separate the icing into two bowls, and mix it with black and green food coloring. Use a pastry bag and round tip to decorate. If you don't have pastry bags or tips, you can use a sandwich bag instead. Just snip the corner of a sandwich bag, fill the bag with icing, and swirl away. You can also create a DIY pastry bag using parchment paper or wax paper.Depending on the type of frosting you use, you should be able to store these Halloween brownies in an airtight container on the countertop for 1-2 days; after that, they should be in the fridge for longer keep. I'd recommend making them either day of or only 1 day ahead of time. Reason being is the brownies, icing, and candy can degrade over time, and you really want these spooky Halloween brownies to look and taste their best.