K9 Mark III first appeared in "A Girl's Best Friend", the 1981 pilot for a series, K-9 and Company, which never materialized beyond the first episode. In this, the character is presented to the Doctor's former companion Sarah Jane Smith (Elisabeth Sladen); together, the two embark on what a number of adventures. Only the first of these is depicted on-screen; several are shown in comic book and audio play adaptations, and others are alluded to by the television series. Mark III made a brief appearance alongside Sarah Jane in the Doctor Who 20th anniversary ninety-minute special The Five Doctors (1983), before appearing properly and for the final time in the revived series' episode "School Reunion" in 2006. By the time of that story, Mark III has fallen into disrepair and eventually sacrifices himself to stop a plot by the alien Krillitane and defeat their leader, Lucas Finch (Anthony Head). In the episode's conclusion, the Doctor presents Sarah Jane with a new K9 to encourage her to continue investigating alien activity; the Doctor "rebuilt" him after the Mark III's sacrifice, implying that he had the same mind and memories as his predecessor while still being a "brand new model".
The Fourth Doctor found that K9 had contracted laryngitis and had lost his voice as a result of this. K9 was left in the TARDIS while the Doctor and Romana II battled the Daleks and Davros. (TV: Destiny of the Daleks) During a later adventure, he remained patiently in the TARDIS, which would imply that his voice had not yet returned. (TV: City of Death) After his voice returned, it sounded quite different and remained so for a while (TV: The Creature from the Pit) before the familiar voice returned. (TV: The Leisure Hive)
He did not use contractions such as "you've" for "you have" and addressed others by titles such as "Master", "Mistress", "Doctor-Master" (to refer to the Doctor) or "Young Master" (Adric, Starkey and in one instance, Clyde). Though he did not seem to resent his subordinate status, he sided with the Doctor's companions over the Doctor and showed a dark side, regarding other artificial intelligences with contempt. (TV: The Invasion of Time, TV: The Wedding of Sarah Jane Smith, TV: Robot Gladiators) He relished a brief chance to act as a figure of power. (PROSE: The Well-Mannered War)
On August 1, 2016, Blue Coat, Inc. (K9’s parent company) was acquired by cybersecurity leader Symantec™. As can be imagined Blue Coat and Symantec had a handful of similar products and unfortunately, it didn’t make sense to maintain two competing products. it was decided to “end-of-life” K9 Web Protection and focus corporate and customer attention on Symantec’s line of Norton™ products.
I use K9 to keep my kids out of offensive web sites especially adult and bad reputation sites. I also like the new "Advanced YouTube Filtering" which seems to be working okay. Now my 11yo daughter can use youtube, which I previously had it blocked. If your kids are old enough talk to them, tell them internet is like a car, it's a great tool, you can use it to go to good places and bad places, so it must be used with responsibility.
A short story, "Moving On", in Virgin Publishing's Decalog 3: Consequences anthology and the Big Finish Productions-produced Sarah Jane Smith audio play Mirror, Signal, Manoeuvre (both written by Peter Anghelides) indicate that K9 Mark III broke down and Sarah was unable to repair it as the replacement circuits would not be invented for several centuries.
“I’ve been down and reached the top, I’ve done it before and I’ll do it again” -@keiseannixon An absolutely fantastic interview with the @Raiders UDFA CB as we talk about his rise from JUCO to playing in his first NFL game! @1stPicksSportshttps://podcasts.apple.com/us/podcast/not-gonna-lie/id1448635934#episodeGuid=78c207df-731c-ace8-a531-2d55d36459e3 …
K9 had a personality very consistent across the models with some contact with the Doctor. He was polite and formal, with pedantry bordering on condescension. Though he often displayed feelings such as sorrow (TV: The Invasion of Time) and self-regard (TV: School Reunion), he often stated that he had not been programmed to have emotions. (TV: Invasion of the Bane)
Damaged by the time winds, K9 Mark II could not cross back into N-Space with the Doctor. He decided to stay behind at the Gateway with Romana II to help her free the remaining Tharils from slavery. (TV: Warriors' Gate) Eventually, Romana II and the presumably repaired K9 returned to their own universe and K9 Mark II came to live on Gallifrey. (PROSE: Lungbarrow, WC: Shada, AUDIO: Zagreus)
K9 Mark 2 had some obvious commonalities with the Mark I that had preceded him. However, as he had almost completely lost his personal memories, he was forced to reacquaint himself with the world around him. Toward this end, he downloaded thousands of human movies onto his memdrive, which peppered his speech with 20th and 21st century English colloquialisms that his "brothers" did not typically employ. (TV: Alien Avatar) Despite his negative opinions of emotions, (TV: Mutant Copper) he asked questions about some, such as fear (TV: Fear Itself) and love (TV: Aeolian). He even showed some, laughing when he saved the day, feeling fear (TV: Fear Itself) and being angry. (TV: Regeneration)
K9 Mark I's mechanisms included rotating ear-probes, telescopic "eye" probe, an extendable nose concealing a powerful laser weapon, flashing lights on the top and the "eye" panel, waggling tail antennae, and ticker-tape tongue. His head could move up and down. His shell was painted in metallic gold/grey. There was a monitor screen on his left flank, though K9 rarely used this during his travels with the Doctor. Around K9's neck was a tartan collar, (being the Family Tartan of the Clan Buchanonn) from which hung a silver disk. (TV: The Invisible Enemy) He was later modified to fly through the vacuum of space. (TV: Curse of Anubis)
The practical challenges of working with the K9 prop have accompanied the robotic pooch in his return to Doctor Who. Producer Russell T Davies told SFX magazine, "Yes, just as we expected, multiple takes [were required] when he bumped into a door or veered off to the left. Lis Sladen did warn us, and she was right!" 2009 saw two different incarnations of K9 appear regularly in two Doctor Who spin-offs: Mark IV in the third series of BBC production The Sarah Jane Adventures, and a re-vamped Mark I in the Park Entertainment production K9.
K9, occasionally written K-9, is the name of several fictional robotic canines (dogs, the name being a pun on the pronunciation of "canine") in the long-running British science fiction television series Doctor Who, first appearing in 1977. K9 has also been a central character in three of the series television spin-offs: the one-off K-9 and Company (1981), The Sarah Jane Adventures (2007–2011) and K-9 (2009–2010). Although not originally intended to be a recurring character in the series, K9 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 K9 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 did so. The character was created by Bob Baker and Dave Martin, to whom rights to the character still belong; consequently, Baker's spin-off series K9, which is not BBC-produced, cannot directly reference events or characters from Doctor Who, though it attempts to be a part of that continuity.