Summarize:

When the jello has had at least several hours to set and is completely firm, remove the brains from the refrigerator. Flip the molds over onto the baking sheet. Gently peel the side of the mold away from the top of the jello to remove the brains. Move the brains from the baking sheet and arrange them on a large flat plate or serving platter. Place one to two drops of red food coloring or raspberry syrup onto each brain to make the brains look bloody. The red food coloring is optional, and the brains will be just as yummy if you choose not to add it. Once the brains have been plated and garnished with blood, you can serve them as is. Or, for an added effect, cut the tops off of each brain to reveal the filling inside. After slicing off the top, lay each top back on the brain, but slightly to the side so you can see the filling. Now your zombie brain jello shots are ready to serve and enjoy!
Remove the shots from the mold. Transfer the brains to a serving platter and add the blood. Slice the tops off the brains before serving.