"Take a look, my dear," he said, opening the bag and tilting it toward James. Inside it, James could see a mass of tiny green things that looked like little stones or crystals, each one about the size of a grain of rice. They were extraordinarily beautiful, and there was a strange brightness about them, a sort of luminous quality that made them glow and sparkle in the most wonderful way.

"Listen to them!" the old man whispered. "Listen to them move!"

James stared into the bag, and sure enough there was a faint rustling sound coming up from inside it, and then he noticed that all the thousands of little green things were slowly, very slowly stirring about and moving over each other as though they were alive.

"There's more power and magic in those things in there than in all the rest of the world put together," the old man said softly.

"But—but—what are they?" James murmured, finding his voice at last. "Where do they come from?"

"Ah-ha," the old man whispered. "You'd never guess that!" He was crouching a little now and pushing his face still closer to James until the tip of his long nose was actually touching the skin on James's forehead. Then suddenly he jumped back and began waving his stick madly in the air. "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, then let the moon do the rest!" (Chapter 3)

James, the hero of Roald Dahl's tale, comes across an old man who has some magical crocodile tongues to show him. NBD.

Roald Dahl's James and the Giant Peach is full of the fantastic...like, you know, a giant peach. It all starts with the old man whom James comes across one day while he's sad. We know that we're in the realm of the magical right when we gaze into that bag along with James and see the little green things stirring about and moving.

Oh, and by the way, they're crocodile tongues. Clearly the old man is well versed in magic; he explains to James that the crocodile tongues have had to go through a very special treatment, involving a witch's skull, the eyeballs of a lizard, and the juice of a porcupine, among other things. This scene's emphasis on the extraordinary and the magical is 100% characteristic of children's literature.

At first, when he looks into the bag, James doesn't realize that he's looking at something spectacular. The crocodile tongues are described as "tiny green things that looked like little stones or crystals, each one about the size of a grain of rice."

But slowly, the passage takes us from the mundane to the magical. The green things seem to "glow and sparkle." And then James realizes that not only are they glowing and sparkling, they're actually moving. In this way, the scene transitions readers from the everyday world that we're all familiar with (where little green things are just little green things in a bag) to the world of the fantastic: glowing and sparking and moving crocodile tongues.