You may be looking for K9 Mark II, who was created by the Fourth Doctor.
K9 Mark 5.694 was an incarnation of K9 created after the Mark I self-destructed. This K9 was associated with Professor Alistair Gryffen. He gave dog whistles to Starkey, whom he called "Young Master", as well as Darius Pike and Jorjie Turner.
- Before Regeneration, see K9 Mark I
K9 Mark I survived the Last Great Time War, despite having been destroyed earlier. (Imperiatrix) Some time later, he went to the year 50,000 and met Zanthus Pia, Head of the Galactic Peace Commission, whom he saw murdered at the hands of Ahab. As he was a witness, Ahab's four Jixen friends attacked him. He and the Jixen were pulled by a Space-Time Manipulator to Gryffen Manor on mid-21st century Earth. After a fight, K9 self-destructed to save the humans in the area. Starkey retrieved K9's regeneration unit, allowing him to rebuild completely, although he had forgotten his former Mistresses, Leela and Romana, and his former Master, The Doctor. After introducing himself, K9 completed his "orientation protocol", determining he was in London.
Alistair Gryffen studied this "Fallen Angel", though K9 could come and go as he pleased. Gryffen didn't tell his employers, The Department, but they saw CCTV footage of the night of the explosion. Starkey showed up after escaping from the Department's virtual reality detention facility. The dog realised that he was human. K9 gave Starkey his dog whistle, to let Starkey call him when he was in trouble and stayed at Gryffen's house, ready for more adventures.
Starkey stayed at Gryffen's with K9 to hide from the Jixen. K9 informed Gryffen that the Jixen was alive and on the move around Dauntless Prison, where the Department kept captured aliens. Starkey decided to go to the prison and get the Jixen before it got him, Gryffen asked K9 to go to the prison and track the Jixen. K9 obeyed but with great unease. When K9 entered the Department exclusion zone, Inspector Drake ordered him attacked by the Department's defense robots . Despite this, K9 helped the gang deal with Jixen.
K9 helped Starkey evade the Department's surveillance. Sometime later, Jorjie came to give Starkey some food when she was called by Darius who told her that Gryffen had gone missing. K9 was able to contact a human soldier from the year 2618, who informed them that the Korven had sent an operative back through time to find a group of scientists who created a system to cool the Earth, Gryffen being one of those scientists. K9 explained that the Korven absorbed all information from the brain and then abandoned the host body leaving it like an empty shell in a process called leeching. Medowin warned them that if they get the data they need from the scientists they would cool the Earth and destroy humanity. Communication was lost just as he was about to give the Korven's weakness. K9 however was acquainted with the Korven's weakness, during the leeching process their entire being was focused on their victim, the only known time when they're vulnerable. The team followed the trail of Phosphane gas traces. When they arrived at the iceworks the Korven took Gryffen to, the team split up. Despite assuring Starkey he was fine he later revealed he was being affected by the Phosphane gas K9 reveals he is being affected by the Phosphane as his behaviour became increasingly stranger. When Starkey saw the Korven leeching Gryffen, he was kidnapped by it. Darius and Jorjie found K9 on the floor, he tried to focus but engaged his self-protection protocol and shut down. Darius decided to take action, he destroys the Korven's Phosphane tank and gains his attention, the Korven prepared to fire but K9 overrid his self-protection protocol and shot the Korven. K9 then shut down, Darius then woke Gryffen. The Korven then got back up; Darius grabbed the Korven's arm before it could shoot him but couldn't hold on. Starkey ordered K9 to fire his Photon Beam which K9 interpreted as "Baked Beans?". K9 shot the Korven with the temperature required to make Baked Beans edible, killing it. Back at the mansion, Gryffen accessed the Department mainframe and erased Starkey's computer encryption code it so that he was no longer a wanted dissident, he then offered a spare room for Starkey and K9 to stay. As they went to bed, K9 emitted the remainder of the phosphane in his systems in a manner similar to flatulence.
After he defeated Ahab, who tried to convince him he murdered Zanthus Pia. He became part of the K9 Unit, being made the responsibility of Gryffen and under the control of Department inspector June Turner. He then foiled Inspector Drake's plan to control the population using Cerulium and experienced fear. He later aided in the of defeat echoes of Gryffen's family and Orthrus, a duplicate of him created by Drake to frame him, and the Bodach. He was then met by Nehetka and Geb of the Anubians, a race his previous incarnation liberated. He was so obsessed with regaining his lost memories that he didn't realise Gryffen, Starkey and Jorjie's takeover by the Anubians. He soon found out when the Anubians attacked the Department, with the help of Darius he was soon able to defeat him.
He later helped Starkey fight the Oroborus, freed the Medes and help one of the last Aeolians find her mate. He then saved a Centuripede and her young from being killed by Drake and absorbed the Hunger swarm which threatened to devour Earth. He and Starkey then went through the STM to 1963 where they rescued Jorjie and saved Darius' great-grandfather William Pike from being arrested and erasing Darius from history. He enlisted the help of the Ukkan librarian Yssaringintinka to rescue Starkey who was trapped on the planet Urlic. He later helped Birdie, a CCPC which implanted human DNA escape from the Department. He then discovered the last of the Etydions and taught Taphony how to be a friend.
Either Inspector Thorne or Lomax found out about K9's regeneration unit and decided to acquire it. Thorne joined forces with Freddie Maxwell, owner of Crashclub involving old robots being made to fight. K9 went undercover as a gladiator and made friends with the robot clowns Chuckles and Boris. He was called to fight the Pain-Maker who was laced with the explosive solarmite, when he was set to self-destruct K9 detected this and fled the explosion. In an attempt to regain his memory and find out his connection to the STM, K9's achieve was scrambled and directives from the STM almost caused him to self-destruct and lose all his memory. However with help of Gryffen and Starkey he was able to override the directives. He later helped Gryffen find the STM's temporal stabilizer from the fallen angel crash-site in Canada where it was revealed to be Korven technology. He later stopped haywire CCPCs when the Last Precinct's plan backfired. After this he was tricked by Thorne to give him his regeneration unit in return for a lost memory chip, however this turned him into a bomb which would make him self-destruct upon encountering Jixey however Starkey helped him disarm himself.
K9 fought valiantly during the botched Korven invasion of Earth that entailed but not without his companions' much needed assistance. After exhausting all his energy during the climax of the failed conquest, K9 retreated to Gryffen Manor where he almost died, his rundown state plunging him into the depths of oblivion. Luckily his regeneration unit homed back to its master and gave him the spark of life, replenishing his power core and using the excess energy to reconstitute his old dog collar. Given a new lease on life, a frisky K9 flew off to celebrate, rejoicing that he had cheated death once more and like always made it out in one piece.
This version of K9 was more upbeat and aggressive than other versions that existed in the universe. Whereas the K9s that travelled with the Doctor tended to apply logic in a somewhat cautious way —frequently arguing why the odds suggested that something couldn't be done —this K9 tended to freely place himself in harm's way. He was also more ruthless than other K9's, killing a Korven, offering to have Drake taken out and threatening him and his CCPCs with liquidation (this may have been a bluff). Unlike other K9s, he gave the title of master, specifically "young Master", exclusively to Starkey. Whereas other K9s commonly referred to all their friends as master or mistress, K9 never referred to Gryffen or Darius as master, nor Jorjie or June as mistress.
He also investigated human emotions in a more thorough way than his predecessors, and even, apparently, experienced the emotion of fear.
Unlike his predecessor, he did not appreciate being called "dog" or "boy".
His use of the English language was far more colloquial than any of his predecessors, because he had downloaded 5000 human movies onto his memdrive, and these were influencing his speech. He did speak more technical sometimes, however, such as when Starkey announced "kicked surveillance butt" K9 vowed to "kick surveillance posterior" whenever possible. When Starkey was attacked by a Jixen, K9 recommended "rapid movement in the opposite direction of the Xenomorph".
K9 Mark 2 was radically altered in design and far more complex compared to Mark I. His ear probes were replaced with larger silver aerials, a set of blue lights on his head flashed when he spoke. Most of his body was dark silver in colour and a silver dog bone was located under his neck. He seemed to have the same capabilities as Mark I but was presumably more advanced. When attacked and incapacitated, he could give his living metal frame downtime to a tune to energy signatures of weaponry with combat conditioning shielding. He was also capable of emitting gas in a manner similar to flatulence. He was able to use a tractor beam to pull an object as large as an adolescent humanoid, he could also use it to absorb microscopic objects. Although he was vulnerable to energy attacks, he was nearly perfectly resilient when it came to explosive forces, as he said, while highly explosive forces were capable of damaging him, the only explosive force capable of destroying him was his own self-destruct function.
This new K9 didn't have any memory of his past life, although he did regain fragments of his memory remembering some of his travels. It is unknown whether he remembers or eventually will remember the Last Great Time War, Romana II or Leela. However as only his memdrive was damaged and database of aliens and planets was left unharmed. It is likely he still knows about planets and races such as Gallifrey, the Time Lords, and the Sontarans.
Behind the scenes
- Although this was a "new" version of K9, it was a new incarnation of K9 Mark I, as opposed to it being a Mark V. This point was made clear in the episode K9TV: The Bounty Hunter.
- K9 Mark 2 was designed by Paul Tams and Alex Kubalsky.