Eknodine

The Eknodine were a species of aliens that took over the bodies of old people in a dream created by the Dream Lord.


 * The Doctor spoke to them as if he knew of them, indicating that they likely exist in the main universe.



Biology
The Eknodine were aliens that could live inside of human hosts, extending their lifespan. Only a green eyestalk could be seen from the mouth, which would spray out a green cloud when attacking. This cloud could turn people into dust. (DW: Amy's Choice)

History
The Eknodine that the Doctor, Amy Pond and Rory Williams encountered said that they were driven away from their home planet and came to Earth, where they took hosts at the Leadworth retirement home to stay inconspicuous. Angered at their loss, they decided to destroy other worlds.


 * Due to the cracks in time being the arc in Series 5, the Enkodine may have been driven from their planet, much like the Saturnynians. Of course, as their presence on Earth was part of a dream, the cracks could not actually have been involved, but the Doctor's knowledge and recent encounters with it could have influenced the dream.

They chased and attacked The Doctor, Amy and Rory after they found out what they were and cornered them in Amy and Rory's house and attempted to gain entry. One, under the guise of Mrs Poggit, killed Rory after climbing up to the top floor window and turned him into dust. Amy and the Doctor decided to kill themselves, hoping that this was the dream, and ran a couple of Eknodine over before crashing into the house and dying. (DW: Amy's Choice)

Behind the scenes
Ha'rik may have been an unused name for them making them one of the three new enemies to appear in Series 5 as mentioned by Steven Moffat as they were rumoured to have been named that.