Doctor(s): 4th Doctor (Tom Baker); brief appearance with the 5th Doctor; cameos in the revived series
Traveled: 1977 – 1981 (two distinct robot units)
Voice actors: John Leeson (primary), with David Brierley and Roy Skelton voicing K9 in some stories
Episodes & Stories
The Invisible Enemy (introduced), Image of the Fendahl, The Invasion of Time, Destiny of the Daleks, City of Death, Full Circle, Warriors’ Gate (departure). Also in K-9 and Company, The Sarah Jane Adventures, and the K9 spin-off series.
Personality
A robotic dog built by the Doctor, K9 is logical, literal-minded, dryly witty and fiercely loyal, often serving as a mobile computer and comic foil.
Interesting Facts
- K9 proved so popular that the production made two distinct on-screen units and spun him off twice.
- The prop was notoriously unreliable on uneven outdoor terrain.
- K9 has appeared in more spin-off shows than perhaps any other companion.
What Happened to the Character
K9 Mark I stays behind on Gallifrey with Leela; K9 Mark II eventually stays behind with Romana in E-Space at the end of Warriors’ Gate (1981); a Mark III is later gifted to Sarah Jane Smith.
The Actor Today
John Leeson has continued voicing K9 across decades of television and audio, well into the 2010s and 2020s.