Place the eggs in a saucepan and cover with cold water, then bring to a boil. Once bubbling, turn off the heat and let the eggs sit for 10 minutes to cook through. Transfer them to cold water to stop the cooking and make peeling easier.
Peel the eggs carefully once they're cool enough to handle. Slice each egg in half lengthwise on a clean cutting board, and gently scoop out the yolks into a mixing bowl, leaving the whites intact.
Add the mayonnaise, mustard, and black pepper to the yolks. Mash everything together until smooth and creamy, adjusting the olive juice to achieve a firm but spreadable consistency.
Transfer the yolk mixture into a piping bag fitted with a small round tip for neat filling. Pipe the filling into the hollowed egg whites, creating a rounded, plump appearance.
Take a small spoon or melon baller and carefully position an olive half onto the center of each filled egg, pressing slightly so it sits securely. This creates the creepy eyeball effect.
Arrange the assembled eyeballs on a platter and refrigerate for at least 15 minutes to let the flavors meld and set. Serve chilled or at room temperature for a spooky presentation.
