Plasmavore

The Plasmavores were a race of blood-sucking near-Humans. They were commonly criminals, murdering people across the galaxy and drinking their blood.

They required blood to survive as their bodies absorbed a lot of salt. The fact that they were near-Human helped them to hide, as they could blend in with Humans on Earth. When they drank Human blood, they could assimilate its properties into their own systems and fool a Judoon alien scanner, appearing Human.


 * The fact that "Florence" was not identified as an alien during what was apparently a lengthy hospital stay involving several medical examinations suggests that either the species was either extremely Near-Human or able to modify their biology to fool less sophisticated scanners without the need for assimilated biomatter.

Some Plasmavore criminals made use of Slabs to restrain their victims before killing them. (DW: Smith and Jones)


 * "Florence Finnegan", the Plasmavore on Earth, described herself as a "survivor", perhaps suggesting that, due to criminal associations, Plasmavores are now a rare species in the galaxy.