In the wood again, she comes across a Caterpillar sitting on a mushroom. He gives her some valuable advice, as well as a valuable tool: the two sides of the mushroom, which can make Alice grow larger and smaller as she wishes. The first time she uses them, she stretches her body out tremendously. While stretched out, she pokes her head into the branches of a tree and meets a Pigeon. The Pigeon is convinced that Alice is a serpent, and though Alice tries to reason with her the Pigeon tells her to be off.