Drain the canned lychees, reserving the syrup for later use. Take one fresh blueberry for each lychee "eyeball. Carefully place a prepared blueberry, inside each hollow lychee. The blueberry should fit snugly inside the lychee, creating the effect of an eyeball. Prick few prepared eyeballs with skewer and few leave for decoration. Set aside.
Rim your glasses with purple sugar. To do this, wet the rim of each glass with a lime round and then dip it into a shallow plate filled with purple sugar. Set the glasses aside tot let the sugar stick.
In a mixing glass, combine the blue energy drink, Sprite, fresh lime juice, and few drops of purple food colouring. Stir gently to mix.
Fill the rimmed glasses with ice cubes and leftover lychee eyeballs.
Carefully pour the prepared mocktail mixture into the glasses, ensuring not to disturb the sugar rim.
Garnish each glass with a lime round on the rim and add a paper straw for an extra spooky touch. Serve immediately!