Terileptus

Terileptus was the home of the Terileptils. Judging by their dependence on soliton gas, the planet might have produced it naturally. (TV: The Visitation)

Terileptus was located near the Darkheart colony, between two of the Mutter's Spiral's spiral arms, beyond Lasky's Nebula. Adjudicator Terrell was persuaded by the Master to use the Darkheart circa 3375 to destroy the planet, marking the end of an interplanetary civilisation. The Terileptil race, however, was not completely destroyed. (PROSE: The Dark Path)