The Hysk were an extinct race of giant, upright insects with multiple calliper-limbs and concentric mandibles. They were known throughout Mutter's Spiral as being "oppressive, totalitarian, unmerciful and antisocial" creatures.
It was UniMedia Franchise Orbital (largest off-world news conglomerate in the Spiral) that sought to exploit these creatures as objects of fear. For hundreds of years, long after their extinction, they generated a hologram (identifying itself as Myskhurr) and reproducing the illegal drug Chronex (which gave the illusion of extending life while ultimately bringing death). All this was to command the ratings in a scandal that nearly ran across the colonies before being exposed by one of their reporters, (Huksley), aided by the Seventh Doctor. (PROSE: The Infinity Season)