Prepare the eggs
Slice the hard-boiled eggs lengthwise. Carefully remove the yolks and place them in a mixing bowl.

Make the filling
Add the Dijon mustard, mayonnaise, and salt to the yolks. Mash with a fork until smooth and creamy.

Fill the eggs
Spoon the mixture back into the egg whites, or use a piping bag (or sandwich bag with the tip cut off) for a cleaner presentation.

Create the spider bodies
Slice about 12 olives in half lengthwise. Place one half (cut side down) on top of each deviled egg to form the spider body.

Make the legs
Slice the remaining olives lengthwise again, then cut into thin strips to form legs.

Assemble the spiders
Place 3–4 olive “legs” on each side of the olive body to complete the spider look.

Serve
Chill slightly if desired, then serve as a spooky snack or appetizer.