"Eyes on the back of your head" was never taken so literally.
WARNING: Spoilers are unmarked.
- The ending of "Blood Brothers": Michael Deighton, fearing death by Huntington's Disease, takes the newly discovered wonder drug Deighton C to live forever. However, it turns out the drug has the side effect of using up all of the user's cell energy, thus turning him into an incapacitated and aging body similar to Tithonus, unable to die but cursed to spend the rest of his life on life support.
- "The New Breed": the Body Horror transformations that the main character Dr. Andy Groenig goes through (which include growing gills, eyes in the back of his head, bones above his stomach, extra keen hearing, and jellyfish-like stinging tentacles on his skin.) Not to mention his increasingly desperate attempts to stop the nanobots culminating in an attempted suicide that fails due to the bots fixing him, which leads to him sacrificing his life by allowing his best friend Dr. Stephen Ledbetter to kill him and destroy the lab containing the remaining nano-bots in a fire. It ends up being for nothing, as the episode ends with Andy's grieving fiancée Judy having cut her finger on a shattered photograph of him. The wound heals immediately, implying that the nanobots have spread to her as well.
- "First Anniversary" is this up to eleven, with its Starfish Aliens. Disturbing, despite the costumes being seen as weird on YouTube.
- The ending of "Breaking Point": Andrew McLaren travels forward in time two days and finds his wife Susan dead in their house, having been shot. It turns out that his attempts to prevent her death are what resulted in it happening in the first place. He then travels back in time to 1993 and kills his younger self just before he was about to meet Susan so that she will live. However, Susan was severely depressed at the time and Andrew was the one who helped her get her life back together. This episode ends with Susan taking an entire bottle of pills with alcohol. The clear implication is that she will not survive the night.
- Karl Rademacher from "Tribunal" is perhaps the most chilling villain depicted in the series, mainly because he lacks any of the supernatural gimmicks of many of the other Monsters of the Week and is just a human. He used his time as a Nazi captain to murder and torture people on a daily basis, first shown shooting a woman in front of her husband and daughter and gleefully gassing hundreds of people at a time. He later murders his own future self when the descendants of his victims send the aged Rademacher back to his old camp.
- The ending of "Flower Child": A plant-based alien, the Last of Its Kind, traveled to Earth via a meteor. It became embedded in the soil of a community garden of a San Francisco apartment building and grew into a strange plant overnight. After it kills Mary Cummings with its stinger, the alien uses the energy that it absorbed in the process to transform itself into a beautiful young woman named Violet. Taking up residence in Mary's apartment, Violet seeks to procreate and produces a scent which men find seductive. She sets her sights on Chris, who has just moved into the building with his fiancée Mia and is experiencing pre-wedding jitters. Chris initially manages to resist temptation due to his commitment to remain faithful to Mia but the landlord Mr. Sylvano is less strong-willed and is killed by Violet for his trouble. Chris eventually succumbs to her charms and they have sex. As a result, Violet obtains Chris' seed and uses it to produce millions of offspring which she ejects from her body through the mouth. Her species will soon spread all over Earth and replace humanity as the dominant species.
- Simon from "Simon Says". Mainly for the creepy aspect of him and his SkeleBot 9000 appearence.
