Eye of newt and toe of frog, wool of bat and tongue of dog.
"Double, double toil and trouble; fire burn, and cauldron bubble. Watch the cauldron blow, watch that fire go. What shall we put in it? A skull, an eyeball, a piece of bone. A bat, a dog! A newt, a frog! Stir that cauldron, round and round! Watch the potion start to froth. It's ready, it's boiling! It's about to pour over the top! Children, come round and round the cauldron. But don't touch! It's very hot! Bring your bowls, and come right up, to savour our delightful Witches Brew. By the pricking of my thumbs, something wicked this way comes."