In Slumber Party, The Wicked Witch of the West uses a summoning ritual to call forth her army of flying monkeys from Oz to Earth once she found a door for the Key to Oz. To perform the ritual, the Witch covered her head, and then put some ingredients into a brass cauldron. Apparently this spell was intended to act like a beacon to her army flying monkeys. After she opened the portal to Oz, she called forth her army by dropping some dried 'tobacco' into the flaming cauldron.