Monstron

Monstrons, also spelt Monstroms, (COMIC: Weapons of Past Destruction) and known collectively as the Monstron Space Republic, (PROSE: Fireball Explosion!) were a race of blue-skinned humanoid chrononauts. (COMIC: The Menace of the Monstrons, AUDIO: The Iris Wildthyme Appreciation Society) They had robotic servants named Engibrains and were led by a President.

History
In October 2065, President Yequan, speaking to four thousand million fighting troops, announced an invasion of Skaro. He proclaimed "The robot-like Daleks of Skaro will feel the strength and might of the Monstrons. We shall conquer all". (PROSE: Fireball Explosion!)

Two Monstrons, Kenex and Yeq, landed on Skaro and made their base inside an extinct volcano. Their attack succeeded in destroying the Dalek City, though the Emperor Dalek and others escaped underground. Their attempt to conquer the planet was defeated by the Dalek which they had captured, which escaped and sacrificed its life to set off a volcanic eruption that destroyed the Monstrons. (COMIC: The Menace of the Monstrons)

The Monstrons then had developed time travel, but The Clockworks council trapped the species in a pocket universe, millennia before the 42nd century. (AUDIO: The Iris Wildthyme Appreciation Society)

Despite their seeming banishment from N-Space, a Monstron Time destroyer once pursued Iris Wildthyme's Celestial Omnibus across time. (AUDIO: The Iris Wildthyme Appreciation Society, Iris Rides Out, Midwinter Murders)

Whilst Jack Harkness was working for the Time Agency, he visited the Fluren Temporal Bazaar to bid on a Monstrom time destroyer. He lost the bid to a pair of Wrightosaur mercenaries. (COMIC: Weapons of Past Destruction)