The old man told James that the green things in the bag came from?

From the text:

"Crocodile tongues!" he cried. "One thousand long slimy crocodile tongues boiled up in the skull of a dead witch for twenty days and nights with the eyeballs of a lizard! Add the fingers of a young monkey, the gizzard of a pig, the beak of a green parrot, the juice of a porcupine, and three spoonfuls of sugar. Stew for another week, and then let the moon do the rest.