The glint vanished as quickly as it had appeared, leaving Thorne to question his own senses, attributing it to fatigue or the trick of light in the unfamiliar lunar landscape. But then, a low, grinding tremor vibrated through his boots, a sensation impossible in the airless vacuum, yet undeniably there, growing steadily from beneath the desolate regolith. He swiveled his helmet toward the source, a point in the vast, cratered plain, and watched in stunned silence as the silvery surface began to crack and heave, slowly at first, then with an agonizing groan that seemed to resonate through his very bones. From the rending earth, a colossal, segmented form began to rise, its immense, pale body shimmering faintly under the distant Earthlight, its blind, ancient head towering over the landscape, a moon worm the size of a mammoth, newly awakened from its slumber beneath the silent, unblinking eye of the moon.
Prompt: a moon worm appeared out of the ground. it was the size of a mammoth