Using a round cookie or pastry cutter, cut circles out of the bread. You need two circles per sandwich (one circle per slice of bread).
Apply your choice of spreads in a thin layer on one side of each circle.
Using 8 pretzels, arrange them as “legs” (4 on each side), placing them so that one-third of each pretzel rests on the bread, fanning out on either side. (See picture.)
Cover the bottom sandwich layer with the top, covering the circle with the “legs.”
Using raisins, chocolate chips, or sliced black olives, make “eyes” for the spider by using a dab of your spread on the eyes and placing them on the top circle.
Spiders never tasted this delicious!