Carefully layer the Bailey's on top. You may want to do this over the back of a spoon.
Using a dropper or a straw drop the Grenadine through the Bailey's layer one drop at a time to help form the brain. Add as much 'blood' as you think the shot needs to create your desired effect.
Notes
Alternatively you could use Amarula Cream Liqueur, Strawberry Schnapps and Grenadine.
Add a few drops of Blue Curacao to transform your brain hemorrhage into an alien brain hemorrhage.
Recipe by isleofhalloween.com at https://isleofhalloween.com/brain-hemorrhage-shot-recipe/