Magic mushroom

When the condor dropped Graham by the hole on the Mushroom Isle leading to the Land of the Leprechauns, he found a mushroom growing nearby. As it turned out, Graham needed to eat the fungus in order to return to the world above ground.

This solution to his predicament is much like the one Alice used in her famous adventures. At one point in Wonderland she met a hookah-smoking caterpillar sitting on a mushroom. Between puffs, the creature told Alice the mushroom was what she needed to change size--one side to make her taller, the other side to make her shorter. Since the girl had already been stretched and shrunk by a variety of cakes and potions, she had no trouble at all believing what the caterpillar said.

In another adventure underground, the caterpillar showed Alice a mushroom and said that if she ate the top of the mushroom, it would make her taller, and the stalk would make her shrink.