Mash egg yolks with a fork into a fine crumble. Add mayonnaise, mustard, salt, and pepper to taste— mix until creamy.

Evenly disperse yolk mixture into egg whites.

Place 1 whole olive on the top of each deviled egg.

Slice the remaining olives width-wise, and then once again in half to make spider "legs". You could also purchase pre-sliced olives and cut them in half to make this step easier.

Place 4 strips of olive on each side of the whole olive to resemble a spider. Enjoy!