Prepare 2 boxes of brownie mix according to instructions on box. Pour into a greased 9x9-inch (23x23-cm) square pan. Bake according to instructions on box.
Cut each tray of brownies into 25 small squares. Form each brownie square into a ball, rolling in palms until smooth.
In a microwave-safe bowl, add the white chocolate chips and microwave in 30 second intervals until smooth, about 1 minute and 30 seconds total.
In a microwave-safe bowl, add the milk chocolate chips and microwave in 30 second intervals until smooth, about 1 minute and 30 seconds total.
Turn a plastic sandwich bag inside out and hold it from the inside with one hand. Spoon ¼ of the white chocolate into the bag. Turn the bag back out making sure chocolate does not fall out the opening. Seal it closed. Cut the corner of the bag, keeping in mind the more you cut off the larger your piping hole will be. Repeat with all of the milk chocolate.
Coat the brownie balls in the melted white chocolate using a fork. Place on a parchment paper-lined baking sheet and chill until chocolate has hardened, about 20 minutes.
Place one of the white chocolate brownie bites onto a clean surface.
Cut the white tips off 2 candy corns, cut each of those tips in half, these will be your mummy’s teeth.
Using the milk chocolate pipe 2 dots on the upper half of the brownie bite for the eyes.
Using the white chocolate pipe a line for the mouth. Evenly place each candy corn piece for each tooth on the line.
Zig zag the white chocolate around the brownie bite making sure not to cover the eyes or teeth.