Squeeze the lime and put the juice in a small cup.
Peel an apple, then using a large metal melon baller, cut out eyeballs.
Dip balls into the lime juice to prevent oxidation.
Using a small sharp object, cut out a circle the size of blueberry. I used a metal pour spout, but a large holed piping tip would also work.
Pop a blueberry in the hole then slice off the excess using a sharp knife.
Use immediately or freeze for later (make sure they don't touch so they don't freeze together).
Pour the blood into the bottom of the glass then fill it with ice.
Squeeze a lime wedge into the glass then top with two ounces of gin.
Finish with two ounces tonic or more to taste.
Garnish with an eyeball. They float, so use a cocktail pick or fork.
For extra effect add a small chunk of dry ice to the drink with the ice.
Make sure to brush up on dry ice safety before your festivities!