Rassilonian Timefly

A Rassilonian Timefly, or Temporanius Clepcydras, were time-sensitive insects. They communicated by exchanging vortex pheromones. Their shells were carcinogenic and artronic, and could cause chronal tumours. 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)