I have told you before about the beautiful Pipevine swallowtail butterfly (see Butterfly Sex Notes) that lays its eggs on leaves of the pipevine.
Soon the eggs hatch into a beautiful, though toxic caterpillar (it picks up toxins from the pipevine leaves).
Eventually, the caterpillar matures and creates a chrysalis in which to pupate. This is so cool! First, it places some silk on the twig (or in this case wall) as a base, then it spins the chrysalis, attaching the top part to the wall with a noose made out of silk!