In a large pot, combine the semi-sweet chocolate chips, sweetened condensed milk, and butter. Heat over low flame, stirring continuously for about 5 minutes until smooth and fully melted.

Once melted, remove the pot from heat and stir in the vanilla extract. To give the fudge its monster appearance, add a few drops of green food coloring and mix until evenly distributed.

Gently fold in the crushed chocolate cookies into the fudge mixture.

Prepare a lined 8x8-inch baking dish with parchment paper. Pour the fudge mixture into the dish, smoothing it evenly.

Before the fudge sets, decorate the top with candy eyeballs and Halloween sprinkles.

Place the baking dish in the refrigerator and chill for at least 2 hours or until the fudge is completely set.

Once chilled, remove the fudge from the dish using the parchment paper and slice it into 1-inch squares.