Place balsamic vinegar in a small saucepan and simmer over medium-low heat until it thickens into a glossy reduction, about 5 minutes. Let it cool slightly.
Arrange the chilled mozzarella balls on a plate or tray and prepare toothpicks or small skewers for assembly.
Pierce each mozzarella ball with a toothpick, inserting a small peppercorn into the center to resemble the eyeball's pupil.
Use damp tweezers or a damp sponge to gently adjust the peppercorns if needed, ensuring they sit centered on the mozzarella.
Place the assembled eyeballs on a serving platter and drizzle the balsamic reduction over them, creating a spooky, veiny effect.
If desired, add tiny drops of red sauce on the mozzarella to mimic bloodshot veins or a creepy slit.
If you want a more intense effect, sprinkle a tiny dash of smoked paprika or red food coloring around the edges for a haunting glow.
Chill the assembled bites briefly in the refrigerator to keep everything firm until ready to serve.
Serve these creepy eyeball bites on a spooky platter for your Halloween gathering and enjoy their playful, eerie appearance and fresh flavor.
