1. Boil the eggs.
Place eggs in a saucepan and cover with water. Bring to a boil, then reduce to a simmer for 10 minutes. Drain and cool under cold water before peeling.

2. Prepare the filling.
Slice each egg lengthwise and remove yolks into a bowl. Mash the yolks with mayonnaise, mustard, relish, and a pinch of celery salt until smooth.

3. Tint the mixture.
Add 2–3 drops of green food coloring, stirring until evenly tinted. Adjust color intensity as desired — you’re aiming for monster-green!

4. Fill the eggs.
Spoon or pipe the mixture into the egg-white halves. For clean presentation, use a small piping bag or zip-top bag with the corner snipped.

5. Create the creepy eyes.
Place one sliced black olive in the center of each egg as the “pupil.” For extra detail, dab a little red food gel around the edges for bloodshot veins.

6. Chill and serve.
Refrigerate for 30 minutes before serving so flavors meld and the color sets beautifully.