The Ship (Shada)

The Ship was a sentient spaceship designed by the Drornidian scientist Skagra. Though originally a regular spacecraft, and a worshipful servant of Skagra, the Ship was convinced by the Fourth Doctor to redesign some of her own circuitry, which resulted in her losing her nigh-religious faith in Skagra (eventually even turning against him) and gaining the ability to dematerialise and travel through the Time Vortex, much like a TARDIS. (PROSE: Shada)