If you’re a fan of origamis, you might like this hand-made spider from several dollar bills. In all you will need 5 bills: “four for the legs, and one to wrap the body”. All the instructions are below.
This picture shows the flat bill wrapping over and trapping the end poking out from the left on the picture above. Make sure that this wrap is very tight, that the legs are squeezed tightly together, or you won't be able to make the body stay together (described later).
Making sure to hold the wrap tightly closed, turn the whole thing over in your hands. While squeezing the side tightly together, kink each of the legs outward, four on each side. (Try forcing the bend to occur over your thumbnail, to prevent pulling the wrapped bill out of shape, or loosening the wrap.)
Okay, this is a rotten picture, but... Take the remainder of the tab (bottom of previous picture, middle-to-right this picture), and tuck it between the legs and the outer wrap on the side that the outer wrap is only one deep.