Mucus
From Tardis Wiki, the free Doctor Who reference
Mucus was one of a variety of bodily fluids that could be squeezed out of the rocks of Nebulax 4. (TV: The Bounty Hunter) A Jixen warrior tracking the K9 Unit left behind a sample of mucus which, when scanned by K9, was confirmed to have been loaded with enough Jixen pheromones to cover a thirty metre tall Kaldarean bedmite. (TV: The Last Precinct)
While looking through the lockers in Little Green Storage, Rory Williams found a room made of mucus. (PROSE: Borrowed Time)
