High Quality Content by WIKIPEDIA articles! K-9, or K9, is the name of several fictional robotic canines (the name being a pun on that word) in the long-running British science fiction television series, Doctor Who, first appearing in 1977. K-9 has also been a central character in three of the series television spin-offs: the unsuccessful K-9 and Company (1981), The Sarah Jane Adventures (2007–2011) and K-9 (2009–present). Although not originally intended to be a recurring character in the series, K-9 was kept in the show following his first appearance because he was expected to be popular with younger audiences. There have been at least four separate K-9 units in the series, with the first two being companions of the Fourth Doctor. Voice actor John Leeson has provided the character`s voice in most of his appearances, except during Season 17 of Doctor Who, in which David Brierley temporarily provided the character`s voice. The character was created by Bob Baker and Dave Martin, to whom rights to the character still belong; consequently, Baker`s spin-off series K-9, which is not BBC-produced, cannot directly reference events or characters from Doctor Who, though it attempts to be a part of that continuity.