Space bug
From Tardis Wiki, the free Doctor Who reference
Acquired on the planet Kandro Four by the Eleventh Doctor as pets for travelling companion Decky Flamboon, a pair of space bugs turned out to be time sensitive. A rough ride in the TARDIS through the vortex caused them to grow and after running amok in the city of Dubai they continued to grow AND evolve. Fed by the time energy they developed speech and wisdom before leaving the planet with their new found mental powers that allowed them to teleport to somewhere where their appearance was less frightening. (COMIC: Pet Panic)