Zygon
The Zygons were a race of metamorphic humanoids from the planet Zygor.
Biology
Zygons were humanoid with cone-shaped heads. Their heads, arms and torsos were covered in suckers and they had deeply inset faces. Their blood was dark red and they spoke in a gurgling whisper. They had an earthy, iron odour and the ability to sting people with venomous barbs on their palms. Zygotes also had venom sacs located on their tongues.
Zygons had a deeply ingrained fear of fire and they could be easily hypnotized by a clock’s swinging pendulum.
They were a hermaphroditic species and reproduced asexually. They started out almost white in colour and more feminine and graceful. As they matured, they became orange coloured, gained their suckers and became more stocky and masculine in appearance.
Technology
Zygon technology was partly biological with an organic look. Their biggest piece of technology was the Skarasen, a large cybernetic ally enhanced creature. The Zygons depended upon the lactic fluid of the Skarasen for their survival.
One of the most important technological discoveries was their use of body-prints. Zygotes would capture specimens, place them in a special receptacle, and take the speciman’s form, mimicking both voice and appearance. This body-print needed to be renewed every two hours with the prisoner kept alive but unconscious. They mostly mimicked humans but could take on the appearance of creatures of diverse sizes and shapes. If they were killed while disguised, the Zygon would remain in that form as a corpse. It was originally believed that the Zygons must keep the original alive in order to maintain their semblance but recent information has proved that they initially needed the body alive but once all information was obtained from the original, their being alive wasn't necessary.
Culture
Zygons were divided into clans, each with a different culture. They measured distance in remarks and were rather fond of board games.
Appearances
Terror of the Zygons (TV)
The Power of Three (TV)
The Day of the Doctor (TV)
The Zygon Invasion/The Zygon Inversion (TV)
Destiny of the Doctors (Video Game)
The Bodysnatchers (Prose)
Sting of the Zygons (Prose)
The True and Most Excellent Comedie of Romeo and Juliet (Prose)
Skywatch-7 (Comic)
Rest and Re-Creation (Comic)
Time & Time Again (Comic)
Hunters of the Burning Stone (Comic)
The Partying of the Ways (Comic)
The Zygon Who Fell to Earth (Audio)
Death in Blackpool (Audio)
Zygon Hunt (Audio)
Homeland (Audio)
Absolution (Audio)
The Barnacled Baby (Audio)
Zygon: When Being You Just Isn’t Enough (Independent Video)