CyberTelosian

The CyberTelosians were an offshoot of Cybermen originating from the CyberFaction's colonisation of Telos.

Characteristics
The CyberTelosians were slim and spoke in a monotone, buzzing voice, emphasising their lack of emotion. (TV: The Moonbase, The Tomb of the Cybermen)

A fatal weakness to the Telosian Cybermen was the combination of solvents known as Polly Cocktail. (TV: The Moonbase)

Technology
CyberTelosians could produce arcs of electricity from their hands to stun, disable and kill. (TV: The Tomb of the Cybermen) They also possessed a cyber-cannon] that could operate in the vacuum of space. The virus Neurotrope X was used by the Telosians to incapacitate humans. (TV: The Moonbase)

Origin
The Twelfth Doctor cited the planet Telos, in addition to Mondas, Earth, Marinus and Planet 14, as a place where they Cybermen rose as a result of parallel universe. (TV: The Doctor Falls)

One account stated that the Telosian Cybermen were originally a race of humanoids, all but identical to Earth humans, native to Telos. Centuries prior to the 21st century, this race sought immortality and so perfected the art of cybernetics. As their bodies became old and diseased, they were replaced limb by limb with plastic and steel. Finally, the circulation and nervous systems were recreated, and their brains were replaced by computers, resulting in the Cybermen. (PROSE: Doctor Who and the Cybermen) Later, forced to leave Telos, these Cybermen took refuge on Mondas, the long lost twin planet of Earth. (PROSE: Doctor Who and the Tenth Planet)

According to the CyberTelosians themselves, specifically the group which attacked the Moonbase in 2070, they were descended from the first space travellers from Mondas, (PROSE: Doctor Who and the Cybermen) the humanoid Mondasians having converted themselves into CyberMondasians. (AUDIO: Spare Parts) These space travellers had left before Mondas was destroyed during the Mondasians' invasion of Earth in 1986. (PROSE: Doctor Who and the Cybermen) According to yet other accounts, the space travellers had only come to Telos as a direct result of Mondas' destruction. All but wiping out the native Cryons, a humanoid species distinct from humans, the Cybermen used their refrigerated cities as repositories of their number cryonically frozen in suspended animation. (TV: Attack of the Cybermen, PROSE: Attack of the Cybermen) According to the CyberHive history, compiled from the Cyber-Documents according to the judgment of ArcHivist Hegelia, the Cybermen did not infact seize Telos and subjugate the Cryons until after their attack on the Moonbase. Considered descendants of the early CyberFaction which left Mondas for Planet 14, these Cybermen were formally recognised as CyberTelosians by Hegelia. (AUDIO: The Cyber Nomads)

Telos being a birthplace of the Cybermen was contentious. Indeed, Bernice Summerfield once corrected one of her students who believed that Cybermen originated on Telos, insisting that Mondas was the true homeworld. (AUDIO: The Crystal of Cantus)

Based from Telos, the CyberTelosians were led by the Cyber-Controller who was the mastermind at the heart of the Cybermen's empire. (PROSE: The Powers Behind the Throne)

Early activity
On 15 October 2070, the Telosian Cybermen attempted to destroy the Earth in order to eliminate humanity, whom they saw as a potential threat to the Cyberman Empire, as well as gaining retribution for the destruction of Mondas. However, this attack was thwarted by the Second Doctor. (PROSE: Doctor Who and the Cybermen, TV: The Moonbase)

Reawakening
By the end of the 25th century, the Cybermen had all but passed into legend when an archaeological expedition to the Telos found the CyberTombs, where hordes of Cybermen waited in cryogenic suspension led by the Cyber-Controller. They were awakened but defeated by the Second Doctor. This tomb was sealed again. (TV: The Tomb of the Cybermen) However, as history recorded, this was not the end of the Cybermen on Telos. It was the hypothesis of the ArcHivists that a surviving group of CyberNomads eventually discovered Telos. Finding the CyberTelosian Controller, they revived and reconstructed him, developing a new form of exoshell that incorporated the most efficient aspects of Nomad and Telosian design, based on the less encumbered Cyber-technology of the Cyber-Controller. Ultimately, a single, new Cyber-subspecies, which the ArcHivists designated CyberNeomorph. Based from Telos, these Neomorph Cybermen proliferated throughout the 26th century. (AUDIO: The Cyber Nomads, PROSE: Killing Ground, TV: Attack of the Cybermen)

Telos' was also not the only CyberTomb. There were dozens across the galaxy and more wars were started off. (AUDIO: The Crystal of Cantus)

Undated events
Following the disappearance of the Time Lords at the end of the Last Great Time War, Telosian Cybermen were among the species that fought to seize the power vacuum they left. (COMIC: Weapons of Past Destruction)

Alternate timelines
In an alternate timeline where Cybermen from the end of the universe allied with Rassilon and began rewriting history, (COMIC: Supremacy of the Cybermen) the Second Doctor was partially converted while on the Moonbase, (COMIC: Prologue: The Second Doctor) pledging his alleigance to the invading Cybermen. This timeline was reversed when the Twelfth Doctor and Rassilon regenerated the universe. (COMIC: Supremacy of the Cybermen)

Other references
Whilst fighting CyberMondasians aboard a Mondasian colony ship, the Twelfth Doctor recalled sealing the Cybermen into their ice tombs on Telos, as well as defeating them on the Moon. (TV: The Doctor Falls)

Behind the scenes

 * Peter Hawkins provided the voice of the Cybermen in The Moonbase and The Tomb of the Cybermen.