Carefully remove the yolks and place them in a small bowl. Add the mayonnaise, mustard, and salt. Mash with the bottom of a small spoon until the mixture is smooth. If the mixture looks too dry, add about half a teaspoon more mayonnaise.
Use a small spoon or small cookie scoop to fill the eggs with the yolk mixture. Slice three olives in half lengthwise—place one-half of each olive on top of the yolk mixture.
Slice the rest of the olives in half lengthwise and then slice each half horizontally into thin strips to make the legs.
Slice the rest of the olives in half lengthwise, and then slice each half horizontally into thin strips to make the legs. Place three legs on each side of the olive on top of the egg yolk mixture. Repeat for the rest of the eggs.
Place three legs on each side of the olive, resting on top of the egg yolk mixture. Repeat for the rest of the eggs.
Cover and refrigerate; add the googly eyes right before serving!
Notes
Don't add the googly eyes or garnish your plate with Halloween candy until you are ready to serve these treats. Both will melt and bleed in the refrigerator.A sharp thin knife such as a fillet knife works best and will give you the cleanest cut when cutting the eggs in half. This kind of knife also works great when cutting the olives to make the black olive spiders.To save time, you can purchase pre-made hard-boiled eggs that have already been peeled to make the deviled eggs. If your eggs are not sitting flat, take a sharp thin knife and trim the bottom, so they will sit without tilting over.A pair of tweezers works like a charm to add the legs and eyes to the black olive spiders' bodies. If you have ever been frustrated because you couldn’t get the shells off of your hard-boiled eggs, check out my post - Perfect Easy to Peel Hard Boiled Eggs! With my method of steaming eggs, the shell falls right off.