The Dark (Forever Dreaming)

 was. . . ''insert brief lead here and use past tense throughout article. See the Manual of style and Layout guide if you have questions.''

Biology
''The Dark appeared as tall men in suits and bowler hats while in Psychspace. They were constantly grinning, and were sometimes shown as having jagged teeth. They each had an individual color (such as red, green, or blue), and this corresponded to everything from the color of the rosettes that they wore to the color of the individual design on their glasses. When the Dreamers let the Dark absorb them, the dreamers took on an appearance similar to that of the Dark, becoming all shadow and gaining one of the designs on their glasses.''

History
''The Dark presumably appeared when the Psychic Squid began trapping great thinkers in Psychspace. They attacked the dreamers and forced them to enter a coma-like state just to keep the dream world from unraveling. When the Doctor and Amy arrive, they attack Amy and then the Dreamers. The Dreamers let themselves be absorbed by the Dark, and then attack the Psychic Squid, destroying Psychspace, and presumably the Dark, in the process, although it's possible some of the Dark's consciousness leaked into the real world. ''