10 Creepiest Star Trek Aliens
5. Flying Parasites
Originally depicted in the Star Trek: The Original Series episode Operation –- Annihilate!, the flying parasites traveled the galaxy imposing their will on other species.
The creatures, which resembled fleshy pancakes, attached themselves to the victim and injected a strand of tissue that intertwined itself with the victim’s nervous system.
The connection between the parasite and its victim was so complicated that attempting the surgical removal of the creature would kill the host. The parasite then imposed its will by inflicting pain. The continuous application of pain led to insanity and death.
In the episode, the parasites killed several people at the human colony on the planet Deneva Prime. The victims included Captain Kirk's brother Sam and Sam's wife Aurelan. They would have wiped out the entire colony but Kirk realized that the parasites hid from the sun and reasoned that they were vulnerable to light. After an experiment that briefly blinded Spock, the Enterprise crew discovered that the parasites were killed by ultra violet light.