Basilisk

The Fifth Doctor knew a version of the story of Noah's Ark in which Noah had to leave behind unicorns, centaurs, basilisks and many other such animals. (PROSE: Perfect Day)

Panda once described the the Roadkill as having basilisk-like stares. (PROSE: Enter Wildthyme)

Behind the scenes
PROSE: My Special Book claims that there was a snake in Harry Potter, when in the real world it was actually a basilisk; this, however, can be explained by George Thompson simply misremembering the story.