In small resealable food-storage plastic bag, place Alfredo sauce; seal bag. Cut off tiny corner of bag. Squeeze bag to drizzle Alfredo sauce in circles over pizza sauce, starting from outer edge continuously to the center. Pull knife through Alfredo sauce, starting from center to the outside edge, changing direction with every pull, to look like spider web. Sprinkle remaining 1 tablespoon olives on top to look like spiders.