X4  Isolation wing of the Bi-Al Foundation (4T).

X29  Earth battle cruiser (QQQ).

X, ANDREW  Harold V's bother.  He was a killjoy who had written books about life on Terra Alpha, and had them smuggled to Terra Omega.  He was drowned in boiling candy (7L).

X-RAY  The laser cannon of the Wheel in Space used X-Rays (SS).

XANA  Kane's lover and the leader of a gang of deadly criminals on Proamon.  She killed herself rather than be captured.  Kane was exiled to Svartos, and had a sculptor create an ice statue of her on Iceworld (7G).

XANXIA (QUEEN)  Evil, warlike Queen of Zanak who had nearly destroyed her planet in endless galactic wars, and was obsessed with eternal life.  She rescued the Captain after he crashed on Zanak and rebuilt him into a cyborg, secretly controlling his machine half.  She then made him build the huge transmat engines which turned Zanak into a pirate planet.  She used the energy stolen from the worlds crushed by Zanak to power time dams to slow the flow of time to a virtual standstill for her dying body.  She then used a cell projector to recreate a younger version of herself, whom she thought would one day become fully corporeal.  She posed as the Captain's Nurse, while secretly ruling Zanak.  But the Fourth Doctor exposed her secret and revealed that her plan was doomed to fail: Xanxia would always remain dependent on the life of her old body and, as the moment of her real death approached, the time dams would need ever greater amounts of energy to slow time even further.  She killed the Captain as he tried to kill her to avenge Mr. Fibuli's death, but he had time to disconnect her cell projector.  She died when the Fourth Doctor and the Mentiads blew up the Bridge and the time dams (5B).

XERAPHIN  Aliens from Xeriphas.  They were among the most highly developed intelligences in the universe, gifted with great mental powers.  Their planet was devastated in the crossfire of the war between Vardon and Kosnax.  Injured by radiation sickness, their entire race physically amalgamated into one intelligence, which planned to rest until the contamination was passed, then regenerate.  The Xeraphin travelled to Jurassic Earth to build a new home.  There, they met the Master who, disguised as Kalid, used their evil side (personified by Zarak) to incorporate them in his TARDIS.  Prof. Hoyter sacrificed himself by joining the Xeraphin, to enable their good side, Anithon, to communicate with the Fifth Doctor.  The Doctor secretly reprogrammed the Master's TARDIS to send the Xeraphin back to a future Xeriphas, which was free of radiation.  They regenerated and went on with their lives (6C).

XERIPHAS  Homeworld of the Xeraphin.  It was devastated in the crossfire of the war between Vardon and Kosnax, forcing the injured Xeraphin to merge into one intelligence.  On Jurassic Earth, the Xeraphin met the Master who succeeded in incorporating them into his TARDIS.  The Fifth Doctor secretly reprogrammed the Master's TARDIS to send the Xeraphin back to a future Xeriphas, which was free of radiation.  They regenerated and went on with their lives (6C).  The Master later escaped from Xeriphas, taking the shape-changing android Kamelion with him (6J).

XERONS  People of Xeros.  They were conquered by the Moroks, who deported the adult population as slave labor.  Later, a weak resistance force, led by Tor, grew among the young Xerons.  With the help of the First Doctor, the Xerons eventually drove the Moroks away and dismantled their Space Museum (Q).

XEROPHYTE  Meglos of Zolfa-Thura was a xerophyte, i.e.: a cactus-like being with great powers (5Q).

XEROS  Home of the Xerons, and location of the Moroks' space museum.  With the help of the First Doctor, the Xerons eventually overthrew the Moroks and freed their world (Q).

XK5  Name of Guy Crayford's experimental spaceship to Jupiter.  The Kraals used it to invade Earth (4J).

XOANON  Sentient computer from the Mordee expedition which had crashed on a nameless planet.  In an unrecorded adventure, the Fourth Doctor, fresh from his regeneration, tried to repair Xoanon but instead turned it schizophrenic.  As a result, Xoanon set himself up as a god, and manipulated the descendents of the Ship's survey team and technicians to evolve into two different tribes, the Sevateem and the Tesh, who were permanently at war with each other.  The Doctor eventually returned and cured Xoanon.  The two tribes were reunited (4Q).

YARTEK  Leader of the Voord commando who tried to take over the Conscience of Marinus.  He was the first to discover a way to be immunized from the Conscience's mind-control influence.  Yartek killed Arbitan but was tricked by the First Doctor and Ian Chesterton, who handed him a fake Key.  He died in the Conscience's destruction (E).

YATES, MIKE   UNIT captain.  He helped the Third Doctor in his battles against the Master (EEE, FFF, GGG,, JJJ, OOO), the Nestene and their deadly Autons (EEE), the Mind of Evil (FFF), Axos (GGG), Azal (JJJ), the Daleks (KKK), Kronos (OOO) and BOSS (TTT).  He was almost brainwashed by BOSS and, possibly as a consequence, later betrayed UNIT by helping Sir Charles Grover to launch his Operation Golden Age (WWW).  After Yates was exposed, he was given extended sick leave and a chance to resign quietly.  He redeemed himself in the fight against the Spiders of Metebelis 3, during which he was wounded and cured by K'anpo (ZZZ).  Yates' image was used by Rassilon to ward off the Third Doctor (6K).

YEGROS-ALPHA  Recreational planet whose specialty was atavistic therapy (5N).


YENDOM  Human slave of the Monoids.  He landed on Refusis with Monoid Two, who killed him for protesting the Monoids' plan to destroy the human race (X).

YENIK  Young Alzarian Outler.  He died at the onset of Mistfall (5R).

YETAXA  Aztec High Priest.  The TARDIS rematerialised in his tomb, and the Aztecs believed Barbara to be his reincarnation (F).

YETI  Peaceful, harmless primates, living in the Himalayas.  The Great Intelligence used robotic replicas of the Yeti, controlled telepathically through small silver spheres lodged in their chest, to frighten travellers away from Det-Sen monastery and protect its first attempt at reincorporation.  This plan was thwarted by the Second Doctor, Prof. Travers, Jamie and Victoria (NN).
 A robot Yeti, brought back to London by Prof. Travers, was donated to Julius Silverstein's private museum.  Reactivated, it and other robot Yetis used Web Guns to launch an attack to capture the Doctor in the London underground.  The Doctor again teamed up with Travers, Jamie, Victoria and Colonel Lethbridge-Stewart to fight the Intelligence.  He succeeded in reprogramming a robot Yeti.  All the robot Yetis later collapsed when Jamie wrenched the Intelligence's mind-draining device from the Doctor's head (QQ).
 A Yeti was used by Borusa as a pawn in the Game of Rassilon (6K).  Real Yetis were taller, less bulky, with longer, silkier, reddish fur and soft, dark eyes.

YOUNG SILURIAN  Junior member of the Silurian triad of Wenley Moor which included the Old Silurian and Icthar.  He was wounded by Major Baker, and later killed Dr. Quinn.  The Young Silurian then tried wiping out Mankind with a deadly virus.  After he learned that the Old Silurian had given the Third Doctor the means to find an antidote, he killed him and became the new leader.  He and the Silurian scientist Icthar then attemped to use a molecular disperser to destroy the Van Allen Belt and render Earth uninhabitable by humans, but he was thwarted again by the Third Doctor, and he had to watch his people return to suspended animation.  He was shot by the Brigadier as he was about to kill the Doctor, and finally perished in the explosions set up by UNIT to destroy the Wenley Moor shelter.  According to some reports, his Silurian name was Morka (BBB).

YRCANOS (KING)  Barbaric King of the Krontep, Lord of the Vingten  and Conqueror of the Tonkonp Empire.  The Mentors were selling laser weapons to Krontep and had kidnapped him to persuade him to become more cooperative.  He fell in love with Peri and staged a rebellion against the Mentors, enlisting Tusa's help.  He was betrayed by the Sixth Doctor who was acting under the influence of Crozier's Cell Discriminator.  The Sixth Doctor later freed him so that he could rescue Peri from having her mind replaced by Kiv's.  The Valeyard used a falsified version of this event, in which Peri was actually killed.  In reality, she was saved by Yrcanos, who killed Crozier, Kiv and Sil.  He then married Peri and returned to Krontep where the two lived happily afterward (7B).

Z9 ELECTRON PACK  Equipment used by the Fourth Doctor on the Sandminer (4R).

Z-BOMB  Doomsday bomb which could split a planet in half.  General Cutler threatened to use it against Mondas, unable to realize it would also endanger Earth.  The Cybermen then tried to use it to destroy Earth, but were thwarted by the First Doctor (DD).

ZA  Caveman member of the Tribe of Gum.  He was the son of the previous chief and of Old Mother.  He was also Hur's lover and Kal's rival for the control of the Tribe.  He eventually killed Kal.  After the First Doctor and Ian helped him rediscover the secret of fire, he also tried to keep them prisoners, but failed (A).

ZAAKROS  Recreational planet whose specialty was to hold the galaxy's largest flora collection (5N).

ZADEK  Taran swordmaster.  He served Prince Reynart (5D).

ZAKE  One of the five Earth colonists from Galsec Seven stranded on Earth circa 15,000 AD, after their ship was destroyed while answering a fake mayday signal.  The Sontaran Styre performed cruel experiments on him to determine the limits of human resistance.  He died when he tried to escape from Styre's robot (4B).

ZANAK  Planet ruled by Queen Xanxia who almost destroyed it in endless galactic wars.  Xanxia rescued the Captain after he crashed on Zanak and made him build huge transmat engines and hollow out the planet, thus turning it into a pirate planet.  Zanak became capable of jumping through space, rematerializing around another world, smothering it, crushing it and mining its mineral wealth.  Xanxia secretly used the stolen energy to power time dams to slow the flow of time to a virtual standstill for her dying body.  She posed as the Captain's Nurse, while secretly ruling Zanak.  The Fourth Doctor came to Zanak looking for planet Calufrax, in reality the second segment of the Key to Time.  With the help of the Mentiads, he defeated the Captain and exposed the Queen.  Eventually, the Doctor blew up the Bridge and used the expanded remains of the worlds destroyed by Zanak to turn it back into a normal world (5B).
ZANIUM  The Jacondans' matter transporter left behind a dust-like deposit of Zanium (6S).
ZANTA  Cully's younger sister (TT).

ZAPHRA  Paralyzing gas used by the Moroks (Q).

ZARA (MADAME)  Manussan fortune teller.  She was a fraud, and became hysterical when Tegan summoned the Mara (6D).

ZARAK  Leading incarnation of the evil side of the Xeraphin.  He was seduced by the Master in his guise of Kalid (6C).

ZARB  President of Inter Minor and Kalik's brother.  He favored liberal policies to improve the lot of the Functionaries and relax Inter Minor's xenophobic treatment of aliens.  Kalik tried to use Vorg's Scope to discredit him, but was thwarted by the Third Doctor (PPP).

ZARBI  Giant ant-like creatures from the planet Vortis, who fought the Menoptera.  They were, in reality, mind-controlled by the Animus, and reverted to their original mindless nature after Barbara managed to destroy the evil entity (N).

ZARGO (a.k.a. MILES SHARKEY)  Former Captain of the Earth ship Hydrax, which was drawn into E-Space by the Great Vampire.  Under his master's influence, Sharkey became Lord Zargo, one of the three immortal vampiric rulers of the Great Vampire's world.  (The others were Lady Camilla and High Councillor Aukon.)  Zargo died when the Fourth Doctor destroyed his master (5P).

ZARINDAS  Incarnation of the evil side of the Xeraphin (6C).

ZAROFF, HERMANN (PROF.)  Scientist, leader in the field of producing food from the sea.  He went mad and, upon locating a surviving Atlantean outpost, he promised its King, Thous, to raise it above the sea.  In reality, he plotted to drain the ocean into Earth's core and thus destroy the planet.  He was thwarted by the Second Doctor, and died fighting with Lolem when the sea finally broke through his laboratory (GG).

ZASTOR  Tigellan leader.  He summoned the Fourth Doctor to Tigella when the Dodecahedron began to fail.  He tried to strike a balance between the religious Deons, led by Lexa, and the Savants, led by Deedrix (5Q).

ZAZZKA  Kastrian commander.  He destroyed Eldrad's space capsule (4N).

ZBRIGNIEV  UNIT sergeant.  He served under Brigadier Bambera during the battle at Carbury against Morgaine (7N).

ZED  Artist who sculpted an ice statue of Xana for Kane on Iceworld.  After he was finished, Kane killed him (7G).

ZEEN-4  Recreational planet whose specialty was historical re-enactments (5N).


ZELANITE  Ore processed aboard the Sandminer (4R).
ZENA  Survivor of the Dalek raid on the space penitentiary where Davros was kept (6P).
ZENTOS  Prosecutor aboard the Ark.  He assumed command after the Commander was taken sick with Dodo's cold virus and almost had the First Doctor and his Companions executed (X).

ZEONS  Inhabitants of Zeos.  They had entrusted the conduct of their unending war against Atrios to the Mentalis computer (5F).

ZEOS  Twin planet of Atrios, located at the edge of the Helical Galaxy, involved in an unending space war against its neighbor.  Zeos was, in reality, deserted, and the war was waged by the Mentalis computer.  Behind it was the Shadow who desired to obtain Princess Astra of Atrios, the sixth segment of the Key to Time.  Atrios and Zeos were saved from mutual destruction by the Fourth Doctor, Romana and Drax (5F).

ZEPHON  Self-proclaimed Master of the Fifth Galaxy.  He was a member of the Dalek Alliance in their Masterplan against Earth.  The First Doctor impersonated him and stole the taranium core.  The Daleks exterminated him as punishment (V).

ZEPPELINS  The First Doctor claimed that he and Susan were once caught in a Zeppelin air raid during World War I (J).

ZERO CABINET  Cabinet built by Tegan and Nyssa to carry the Fifth Doctor to Castrovalva (5Z).

ZERO POINT  White nothingness which was the point of intersection between N-Space and E-Space.  It was there that the Tharils' Gateway was located (5S).

ZERO ROOM  Neutral environment inside the TARDIS where the Fifth Doctor could complete his regeneration while being isolated from the rest of the universe (5Z).

ZETA MINOR  Planet on the edge of the known universe, beyond Cygnus A, as distant from the Artoro Galaxy as that was from the Anterides.  It was the location of the Black Pool, a gateway to an anti-matter universe.  By removing some anti-matter, Prof. Sorenson created a crisis during which anti-matter creatures attacked a Morestran ship.  The Fourth Doctor eventually returned the anti-matter to Zeta Minor (4H).

ZETA POWER LINKS  Component of the Sandminer's propulsion system (4R).

ZEUS  Most powerful of the gods of the Greek pantheon.  During the Trojan War, the First Doctor was mistaken for Zeus (U).

ZEUS IV  Space capsule monitored from the Snowcap Space Tracking Station at the time of the Mondasian Cybermen invasion.  It disintegrated under Mondas' gravitational pressure (DD).

ZEUS V  Space capsule piloted by Terry Cutler.  It was launched in an effort to rescue Zeus IV (DD).

ZIGMA EXPERIMENT  Flawed time travel experiment devised by Magnus Greel.  Greel and the Homunculus used its Time Cabinet to travel from the 51st Century to the 19th Century.  Because it relied on Findecker's theories, the Zigma Experiment was a failure.  Greel's metabolism was distorted by his use of the Time Cabinet, and he would have perished with cellular collapse if he had not stolen other humans' life essences.  If the Fourth Doctor had not prevented Greel from using the Time Cabinet again, the Zigma Experiment would have destroyed most of London (4S).
ZIL  Planet incorporated into Tryst's CET (5K).
ZILDA  Crewmember of the Sandminer.  She was killed by the Robots of Death.  Her brother killed himself to escape from the robots, and Uvanov was blamed for his death (4R).

ZODIN  Nicknamed the "Terrible".  She was a threat that the Doctor would face sometime in the future (6K, 6T).


ZOLDAZ  Tower Guard on the Great Vampire's world (5P).

ZOLFA-THURA  Planet located in the Prion planetary system.  It was the seat of a great technological civilization.  The Zolfa-Thurans destroyed themselves in a war between those (led by Meglos) who wanted to use the Dodecahedron as a weapon, and those who did not.  Meglos survived.  Ten thousand years later, he managed to take the Dodecahedron from Tigella, where it had been taken by the leader of the Zolfa-Thuran peace party, back to Zolfa-Thura.  But his plans were thwarted by the Fourth Doctor and he, along with the planet, perished in the Dodecahedron explosion (5Q).

ZOLFA-THURANS  Race of xerophytes, i.e.: cactus-like beings, with the power to take over other bodies and change shapes.  Meglos was the last survivor of the Zolfa-Thurans (5Q).

ZOMBIES  Creatures manufactured by the Exxilon City to protect itself against invaders.  They were destroyed by the Daleks (XXX).  Also see VAMPIRES.

ZONDAL  Varga's second in command.  He was one of the Ice Warriors brought back to life in 3000 AD.  After he was disabled by the Second Doctor, who threw ammonium sulphide in his face, he died in the explosion of Varga's ship (OO).

ZONES  Political entities which made up 21st Century Earth and succeeded the Blocs (PP).

ZORAC  Cardinal and Member of the High Council of the Time Lords of Gallifrey.  He voted to condemn the Fifth Doctor to death when Omega threatened to return to this universe by taking over his body (6E).  He was probably killed in the Death Zone (6K).

ZUKO  Elder of Sarn (6Q).

ZYGONS  Aliens with shape changing powers.  Circa 1676 AD, the crippled spaceship of the Zygons landed in Loch Ness.  Three hundred years later, their leader, Broton, learned that their homeworld had been destroyed in a stellar explosion, and that his people's space fleet was looking for a new home.  He decided to conquer Earth, and used the Skarasen to sink three oil rigs.  Impersonating the Duke of Forgill, Broton planned to destroy a World Energy Conference.  The Zygons' spaceship was destroyed by the Fourth Doctor, and Broton was shot by the Brigadier (4F).

ZYTON-7 (a.k.a. ZEITON-7)  Extremely precious mineral found only on Varos.  The Galatron Mining Corporation tried to keep Zyton's prices low, but was thwarted by the Sixth Doctor, who had gone to Varos because he desperately needed Zyton-7 to keep the TARDIS functioning (6V).