In 4 microwave safe bowls, place the 4 different colors of chocolate and microwave in 30-second intervals until melted and smooth.
12 ounces purple melting chocolate, 12 ounces green melting chocolate, 12 ounces orange melting chocolate, 12 ounces black melting chocolate
On a tray or baking sheet lined with parchment paper place dollops of the colors all over the lined sheet pan and swirl them together.
Separate the sandwich cookies and place 2 cream side up next to each other to create eyes.
6 chocolate sandwich cookies
Do the same with the smaller cookies and add M&Ms to make the pupils. Add as many sets of eyes as you like.
6 Mini chocolate sandwich cookies, Mini M&Ms, Regular M&Ms
Sprinkle the Halloween sprinkles over the bark.
Halloween sprinkles
Let the bark set either on the counter. If you want it to set faster, place in the refrigerator for 20 minutes.
Break into pieces.