Spread peanut butter on a cracker and top with another cracker. Repeat the procedure until you have 10 bites. Open the candies and with the help of your hands give each candy a round shape. Insert into each candy 3 pieces of pretzel cookies on each side for a total of 6 in each ball. Glue the sugar eyes to each candy. Once the spiders are formed, place each one on the cookies, securing them with a little peanut butter to stick them.