A sentient, spaceborne entity that stretched across eight hundred thousand kilometers of space, with a width of about four hundred thousand kilometers. The creature's length measured roughly twice the combined diameters of Jupiter, Saturn, and Neptune. The cloud, which originated in another galaxy, sustained itself by devouring entire planets, such as the uninhabited planet Alondra in the Pallas XIV system. When the cloud moved toward the populous neighboring world of Mantilles on stardate 5371.3 (2269), the crew of the U.S.S. Enterprise intervened, using Commander Spock's Vulcan telepathic talents to persuade the entity not to consume this planet, thus saving the lives of its 82 million residents.