K9

K9, also spelled out as either K-9, or K•9, is a fictional robot featured in the British television franchise Doctor Who. The robot was introduced in the original series as a companion to the Fourth Doctor, and has also been a loyal ally to the Doctor's humanoid companions as well. K9, throughout his various iterations, has also been associated with Sarah Jane Smith and, for a brief time, the Tenth Doctor as well. K9 has made appearances on the 2005 Doctor Who revival series, the spin-off series The Sarah Jane Adventures, and has also been the feature character in his own K-9 television series. On the original series, K9 was voiced by actor John Leeson.

History
K-9 frequently played chess against the Doctor on the TARDIS, and often won.

Characteristics

 * Refers to the Doctor as Master and calls the Doctor's female companions by the title Mistress.


 * K-9 has been programmed with all championship chess games since 1866.