Space Leech

Space Leeches were green flying creatures which attached themselves to people's heads and sucked the life out of them. They had six main appendages: two long frontal claws, two long limbs for grabbing their prey and two shorter limbs at their back end. Their fleshy mouth was a sucker-shaped funnel with razor-sharp teeth and a central proboscis for a tongue that attached to victims' heads.

They travelled in space, but their level of technology was unknown. When a spacecraft crashed in London on Earth April 2010, Space Leeches swarmed from the wreck and attached themselves to the heads of Londoners, sucking the life out of them. They were susceptible to a highly contagious virus manufactured by the Eleventh Doctor from a cold virus carried by a young lad called Stephen. Detaching themselves from the virus-carrying people, they were attracted by the Doctor’s biology and were last seen following the Doctor into his TARDIS. (DWA: Attack of the Space Leeches!)