Preheat your oven to 350°F (175°C). In a large mixing bowl, combine the chocolate cake mix, eggs, water, and vegetable oil. Whisk or mix on medium speed until smooth for about 2 minutes.

Line a cupcake pan with paper liners and fill each cup about two-thirds full with batter. Bake for 18-20 minutes or until a toothpick comes out clean. Allow to cool for 5 minutes before transferring to a wire rack.

While cupcakes cool, prepare the frosting by beating softened butter until creamy. Gradually add powdered sugar and cocoa powder, then mix in milk to reach desired consistency. Beat for 2-3 minutes until fluffy.

Once the cupcakes are completely cool, generously frost each with chocolate frosting using a spatula or piping bag.

Insert a chocolate-covered pretzel at an angle into the frosting of each cupcake to form bat wings. Sprinkle black sprinkles on top.

Place two chocolate morsels or candy eyes on each cupcake for the bat's eyes. Press gently to secure.

Display your cupcakes on a fun platter and enjoy with friends and family!