K9 (K9: Deja Who)

A version of K9 appeared in various points in time and space. (NOTVALID: K9: Deja Who)

Biography
In the "present day", K9 appeared in London where he thwarted the 2005 Nestene invasion of Earth. Eluding the Auton dummies, K9 collected ice to enhance his photon beam, which allowed him to defeat the Auton Mickey Smith. Confronting the Nestene Consciousness in its underground lair, K9 used a vial of anti-plastic to destroy it.

Circa "5 Billion AD", K9 appeared in Platform One, where he intercepted remote-controlled spider droids through maintenance corridors and deactivated them before they could shut down the sun filters. K9 then proceeded past the giant revolving fans before switching on the shields which protected the space station from the Sun, saving everyone onboard bar Lady Cassandra O'Brien.Δ17, the controller of the spiders who was exposed to the heat which caused her to explode.

Later in the "present day", K9 appeared in 10 Downing Street where he eluded members of the Slitheen family in 10 Downing Street as he collected vinegar which he used to create bombs which he used to destroy the Slitheen leader. K9 then proceeded to shut down the Slitheen's advertisement beacon which offered the planet Earth as scrap.

K9 appeared in 1941, where nanogenes from the future had infected the citizens of London. Avoiding British Army soldiers and Empty Child zombies, K9 collected the nanogene clusters and returned them to the Chula ambulance.

Later in "5 Billion AD", K9 appeared in the New New York Hospital on New Earth, where the Sisters of Plenitude's plague-infected human lab rats had escaped and proceeded on a rampage through the corridors and wards of the hospital. Outmaneuvering the Catkind nuns who attempted to stop him, K9 collected five different coloured vials of vaccine to create a supercure which he plugged into the hospital fire sprinkler system to save everyone. (NOTVALID: K9: Deja Who)

Features
K9 was armed with a photon beam which proved effective against Auton dummies and most Raxacoricofallapatorians. However, both the Auton Mickey Smith and the leader of the Slitheen proved immune to the beam. To defeat the Auton Mickey, K9 collected ice which he used to modify his beam. By collecting vinegar, K9 could create bombs capable of harming and ultimately destroying the Slitheen leader.

K9 proved vulnerable to attack from Auton dummies, Raxacoricofallapatorians, Empty Child zombies, the gunfire of British Army soldiers in 1941, and patients at the New New York Hospital. (NOTVALID: K9: Deja Who)

Behind the scenes

 * This unidentified version of K9 features in the video game NOTVALID: K9: Deja Who, which features him resolving several Doctor Who episodes in the absence of their corresponding incarnation of the Doctor and their companions. Namely, the five levels of the game are respectively derived from TV: Rose, The End of the World, Aliens of London/World War Three, The Empty Child/The Doctor Dances and New Earth.
 * The K9 in K9: Deja Who is portrayed by K9 voice actor John Leeson via archive audio of K9 Mark III from TV: School Reunion.