Glasgow Nights (Doctor Who RPG)
Shapeshifting alien species
Zygons are a race of shapeshifting aliens. They are capable of taking the form of humans to whom they have connected using their body-print technology.
“Zygons in their natural state are characterised by a large, cone-shaped head and a distinctive orange skin covered with suckers. Humanoid in shape, they are usually slightly taller and more well-built than an average human. One of the Zygons’ most fearsome weapons are their terrible stings, which could kill or stun their victims.” (p. 176, Adventures in Time and Space, 50th Anniversary edition)
Before the collapse of the original Torchwood Two, they had heard rumours of a Zygon infiltration of an ultra-secret (so secret that its location isn’t known) UNIT facility known only as the Black Archive. According to these rumours, only the direct intervention of the Doctor saved the facility from ruin.