Trapezium

Trapezium was a planet home to a fabled group of posthumans with elongated limbs. (PROSE: The Baker Street Dozen)

Behind the scenes

 * Half a decade after the release of Tales of the Great Detectives, the Thirteenth Doctor mentioned in the television story The Halloween Apocalypse that she and Yasmin Khan had participated in a "high-gravity circus workshop" on a planet called Trapezium Seven. It is unknown if this was an intentional reference and, at any rate, whether the two planets can be understood to be the same; this is however unlikely, as "high gravity" would imply inhabitants with short, stout limbs rather than elongated ones. It is probable, however, that both Trapeziums are part of a single solar system, as per usual planetary naming conventions, and that the lower-gravity Trapezium has a number which went unmentioned in The Baker Street Dozen.