Fill 2/3rds of a shot glass with white sambuca, and layer Kahlua down side of glass. Allow it to settle at the bottom. Drop in small amounts of advocaat and cherry advocaat. The advocaat will seperate giving the look of a brain.
Using a straw suck out half of the concoction, shot the remainder then immediately cup your hand over the shot glass, insert the straw between you fingers and suck out the vapours.