DoctorDoctor Who Guide

K-9 Mark IV

Last updated 20 April 2015

K-9 Mark IV - Image Credit: BBC
Image Credit: BBC (this image appears for illustrative purposes only and no attempt is made to supersede any copyright attributed to it)

K9 Mark IV was an intelligent robot in the form of a dog that was a companion of Sarah Jane Smith and subsequently Luke Smith, also serving as their beloved pet. He was a gift from the Tenth Doctor to Sarah Jane to replace his previous model.

K9 Mark IV was the fourth in the line of K9 robots. He was based upon the original K9 Mark I designed by Professor Marius in 5000, and which travelled with the Fourth Doctor and Leela. In the late 1970s, the Doctor had gifted K9 Mark III, an improved version of the first two K9s, to his former companion, Sarah Jane Smith.

Mark III was eventually destroyed fighting off a Krillitane invasion, and so Mark IV was presented to Sarah Jane as a replacement by the Doctor, by then in his tenth incarnation.

Biography from the TARDIS Data Core article, licensed under CC-BY-SA