"Skunkey" was a term coined by Clara Oswald to describe a species of creatures resembling both a monkey and a skunk that could be found on the planet of Isen VI around the 25th century.
Skunkeys were artificially created by Dollar Intergalactic in the process of Terraforming the planet. Their creation resulted from the use of hyper-evolution genes, which caused all species on Isen VI to rapidly evolve over the course of three years. They were intended to be harmless, however, Rann-Korr's meddling with the terraforming process imbued them with aggressive features. They grew sharp teeth, and began to hunt in packs.
Skunkeys possessed a rudimentary primitive language: "chakka-chakka" was used to show interest, "shakka-shakka" was an attacking cry, and "akka-akka" was a cry of fear.
They could be repelled with sonic pulses in the range not audible to humans and Time Lords. When a skunkey stole Clara's hat she chased it to a group of skunkeys who proceeded to attack her, only rebuffed with the use of the Twelfth Doctor's Sonic screwdriver.
When Kano Dollar crash-landed in the Isen VI jungle, he was attacked by a group of skunkeys.(COMIC: Terrorformer)