Place the eggs in a large pot, cover with cold water by 1 inch, and bring to a rolling boil. Cover, remove from the heat, and let stand 12 minutes. Drain and transfer to a bowl of ice water 10 minutes.

Peel the eggs carefully, then slice each in half lengthwise. Pop the yolks into a bowl and arrange the whites on a serving platter.

Mash the yolks with the mayonnaise, mustard, pickle relish, salt, and pepper until completely smooth and creamy. Spoon or pipe the filling into the egg white halves.

With the black food-coloring marker, draw a small spider web on top of each white — three concentric circles crossed by a few radiating lines.

Halve each black olive. Place one half on each egg as the spider's body and cut the remaining halves into thin strips for the legs.