Rassilonian Timefly

A Rassilonian Timefly, or Temporanius Clepcydras, were time-sensitive insects. They communicated by exchanging vortex pheromones. Their shells were carcinogenic and artronic. They were hunted mercilessly, so much that when the Eleventh Doctor discovered a pair, he believed them to be the last in existence. (COMIC: The Judas Goatee)