Wrap the small ball's wire around the base of the larger ball; set aside. Make legs by cutting four lengths of silver tinsel wire about 2 1/2 inches long. Twist the wires together at their centers, and then pull apart, bend, and shape them into legs.
Hot-glue the center of the legs to the middle of the body. Finish by hot-gluing the silver balls together. Hang the spider on its web, in a prominent spot on your tree.
Two wired silver Christmas balls, one about half the size of the other (ours are 1/2 and 1 inch in diameter), form the spider's body.