"Hisk koala"
From Tardis Wiki, the free Doctor Who reference
The Sixth Doctor once hinted that there was a kind of "Hisk koala" — that is to say, a koala-like creature from the planet Hiskith. He said that the Great Intelligence used these so-called "koala" to take over that world, in the same way it used Robot Yeti in some of its attempts to take over Earth. (PROSE: Millennial Rites)
