Icthar

"These human beings will die as they have lived. In a sea of their own blood"

Icthar is a Silurian antagonist in Doctor Who. He is the secondary antagonist in "Doctor Who and the Silurians" and the main antagonist in "Warriors of the Deep".

In "Doctor Who and the Silurians", he was portrayed by the late Pat Gorman and voiced by the late Peter Halliday, who had played Packer in the previous season's "The Invasion". In "Warriors of the Deep", he was portrayed by Norman Comer.

Biography
Icthar was one of the Silurians in the colony at Wenley Moor who were accidentally revived in the 20th century to discover that, during their millions of years of slumber, humanity had evolved to be the dominant life-form. Icthar favoured the policies of the belligerent young Silurian Morka over their peaceful leader Okdel. While Okdel attempted to talk peace with the Doctor, Icthar and Morka plotted to infect their human captive Major Baker with a virus that was lethal to mammals. They then released Baker, who spread the virus first to the other occupants of the human research base and then throughout London. When they learned Okdel had released the Doctor with a sample of the virus, Morka and Icthar killed him, with Morka taking over as new leader.

When it was discovered the Doctor had found a cure for the virus, Morka and Icthar formulated a new plan. They took control of the human base, using its cyclotron and their own technology to attempt to alter Earth's atmosphere, letting in high levels of ultra-violet radiation that would kill all humans but allow reptiles to thrive. The Doctor overloaded the equipment, threatening to send the base's reactor into meltdown. The Silurians retreated to their shelter and Icthar and the others returned to hibernation. Morka stayed behind to supervise things, setting the equipment to revive them in a hundred years and telling Icthar he would be leader then. Icthar and the others were believed killed when UNIT blew up the shelter.

In fact, the revival presumably went ahead as planned, since Icthar was active again in the late 21st century, assisted by two other Silurians, Scibus and Tarpok. Finding Earth in a cold war situation with two power blocs posed to annihilate each other, Icthar planned to gain control of a nearby seabase and trigger its pre-programmed missile strikes, which would prompt a retaliation from the other side and start a war that would wipe out humanity. He enlisted the aid of the Myrka and a squad of Sea Devils commanded by Sauvix.

Although the Myrka was killed in the attack, the Silurians and Sea Devils successfully took over the base, killing most of the crew. Icthar encountered the Doctor again and bore him no ill, offering to let him and his companions leave once his plan was completed, but also made it clear he had no intention of seeking peace with the humans. As the countdown for launch began, the Doctor arranged to have the base flooded with hexachromite, lethal to reptiles, in the hope of bargaining from strength. Icthar and his followers were quickly overcome by the gas but Icthar recovered enough to see the Doctor trying to halt the countdown. He grabbed a gun at fired at him, but instead struck the base commander, Vorshak, fatally wounding him. Turlough wrestled the gun from Icthar and killed him with it.

Trivia

 * It seems to have been the intention of the production team that Icthar, first named in "Warriors of the Deep", was the unnamed Silurian scientist from "Doctor Who and the Silurians" but this was not made entirely clear, with the Doctor merely stating Icthar was the last survivor of the Silurian Triad (the other two presumably being Okdel and Morka), that he had met him in an earlier incarnation and believed him to be dead. The novelisation and other sources make it clear they were the same person. However, this was not universally adopted, and further confused by the fact that, prior to "Warriors of the Deep" being made, the novelisation Doctor Who and the Cave Monsters had named the Silurian scientist as K'to. The novel The Scales of Injustice portrays Icthar and K'to as separate characters, with the Third Doctor speaking to the former by a videolink, but contradicts "Warriors of the Deep" by portraying Scibus and Tarpok as the other members of the Triad rather than Icthar being the sole survivor and provides no explanation as to why the Fifth Doctor believed him dead.