Type 18

According to a nightmare the Fifth Doctor had under the influence of the Celestial Toymaker, a Type 18 TARDIS was stolen by the First Doctor, Rallon and Millennia when they left Gallifrey in search of the Guardians. Rallon was not impressed by the lack of comfort the TARDIS possessed, and he claimed that two other models would have been more comfortable - the Type 30 Mark III TARDIS, and the Type 35. The TARDIS took them to the Celestial Toyroom, where only the Doctor survived to return home. (PROSE: Divided Loyalties)