K-9 is a mechanical dog sent to Sarah as a gift and becomes her partner in the investigation. He analyzes soil, stuns Peter, and secretly monitors George Tracey's household, discovering the planned ritual murder of Brendan. K-9 helps Sarah work out when and where the sacrifice will happen, then uses his blaster to stop it.
The Doctor's robotic dog whose explosion in Brighton after chasing a ball into seawater prematurely ends the holiday and forces the Doctor and Romana to seek refuge on Argolis.
The Doctor's robotic companion. He assists the Doctor, Romana, and Garron in escaping their cell and guides them to the catacombs during the mission to secure the Key to Time segment.
K9 is the Doctor's robotic companion. On Zeos, he communicates with Mentalis, which then declares the war over. The Shadow later abducts and controls him, but Drax frees him. K9 helps the Doctor and Drax infiltrate the Shadow's lair by pretending to remain under the Shadow's control.
The Doctor's robotic companion who helps plan the counterattack, traces the Vardans' homeworld through the forcefield, assists in constructing the Demat Gun, and decides to stay on Gallifrey with Leela.
Serves dual roles: as K9, a robotic assistant created by Prof. Marius that aids the crew; as the Nucleus, the sentient virus entity infecting the Doctor and attempting to spawn on Titan Base.
K-9 is the Doctor and Romana's robotic companion. While the Doctor is away, K-9 helps Professor Rumford repair the projector, enabling them to bring Romana back from the prison ship. His practical assistance supports the Doctor's investigation and helps reunite the travelling group.
John Leeson has 52 screen credits in a career dating back to 1963. Signature works include K-9 and Company: A Girl's Best Friend, The K-9 Files, Doctor Who: The Sun Makers. Explore the interactive character relationship maps on each title page to trace how their roles connect across franchises.
Related entry on Wikidata (Q1812342), public domain (CC0).
