Preheat oven to 350F and line a 9"x9" pan with parchment paper.
In a medium mixing bowl, add in your brownie mix, oil, water and egg. Mix well together until there are no clumps.
Pour the batter into the 9"x9" pan and spread it in an even layer to the corners.
Bake in the oven for 25-30 minutes or until a toothpick is inserted in the middle of the pan and comes out almost clean.
Melt some white chocolate in a small bowl, and on a sheet of parchment paper, spread out small spoonfuls of white chocolate and roughly shape them into little ghosts. Add a mouth and cute eyes with the black icing pen and place in the freezer for 20 minutes to harden.
Once your brownies have cooled COMPLETELY, place each ghost on top!
Serve and enjoy!