Not every great horror series gets the buzz it deserves. Some slip quietly under the radar, overshadowed by splashy new releases or buried in streaming menus like a cursed VHS in the back of a thrift store. But hidden in the shadows are shows that deliver the chills, thrills, and “watch-through-your-fingers” moments horror fans crave—without the overhype.
This is Part 1 of our roundup of underappreciated (or under-discussed) horror series that are absolutely worth your time. From slow-burn dread to breakneck gore, each one brings something fresh, frightening, and unforgettable to the genre.
Don’t Let It In Your Ear: Why Parasyte: The Grey Is Your Next Binge
In this Korean sci-fi horror series—a spin-off of the manga of the same name—mysterious parasites fall from space and invade human bodies by entering through the ears, consuming their hosts’ brains, and fully taking over. Once in control, they unleash terrifying transformations: heads split open to reveal long, whip-like tentacles tipped with razor-sharp claws, reminiscent of a Stranger Things Demogorgon but even more grotesque. These creatures use their human vessels to hunt, kill, and spread, creating a growing force on Earth. They communicate through a high-frequency signal and manipulate religion to form a secretive community that ensures their survival.
To combat them, a police unit called "Team Grey" is formed, led by the relentless Choi Jun-kyung. Their most unusual weapon? A captured parasite encased in a containment suit and helmet, used like a hunting dog to track down others of its kind.
Enter Su-in, a young woman violently attacked and left for dead by a deranged customer. As she lies unconscious, a parasite finds her—but due to her critical injuries, it fails to take full control. Instead, it heals her and forms a fragile coexistence, creating a rare human–parasite hybrid. If Su-in can learn to communicate with the being inside her, she may become humanity’s last hope—before there’s no one left to save.
Praised by fans for its stunning visuals, intense body horror, relentless action sequences, and tightly focused story, Parasyte: The Grey delivers a visceral punch from start to finish. The only consistent critique is a slight lull in pacing during the middle episodes. A perfect fit for fans of Train to Busan, Sweet Home, and Attack on Titan, this six-episode limited series on Netflix is easily bingeable—ideal for a day when you’d rather stay inside… just in case something tries to crawl into your ear.
Inside No. 9 — Dark, Twisted, and Perfectly Self-Contained
Inside No. 9 is an anthology series with dark, macabre humor and unsettling twists — ranging from family drama to pure horror. Spanning nine seasons from 2014 to May 2024, each season features six episodes. Season (or series) one is available on Apple TV, with every episode streaming on BritBox.
The premise: a chilling, often twisted peek behind the front doors of locations numbered 9, with every story unfolding in a confined setting. Created and written by Steve Pemberton and Reece Shearsmith, known for The League of Gentlemen, the duo ensures that at least one of them appears in every episode. While the stories have no direct plot connections, each contains hidden easter eggs that subtly link it to the others.
Don't want to start at the beginning? Here is the internet consensus (as much as the internet ever agrees on anything) of the best five episodes of Inside No. 9:
- "The 12 Days of Christine" (Season 2, Episode 2): Praised for its exceptional writing, directing, and performances, this episode departs from the series’ usual black comedy, delivering emotional depth through a poignant, dramatic narrative. Told in a non-linear sequence of twelve pivotal days over twelve years of Christine’s life—each shadowed by a mysterious stranger—it culminates in a signature twist (no spoilers here).
- "Dead Line" (Halloween Special, 2018): This special live episode was billed as a Halloween tale about Arthur Flitwick (Steve Pemberton) finding a cell phone in a graveyard and stumbling into a supernatural nightmare while trying to return it. Mid-broadcast, “technical difficulties” derailed the show, prompting the network to air a repeat episode—also mysteriously plagued with glitches and supernatural disturbances. Viewers caught glimpses of off-camera chaos, including the cast reacting to the “failed” transmission. Some praised the ambitious, inventive storytelling, while others found the staged mayhem too chaotic to follow. Either way, it remains one of the series’ most unique episodes.
- "A Quiet Night In (Season 1, Episode 2): An homage to silent cinema—particularly the slapstick of Charlie Chaplin, whose granddaughter appears—this mostly wordless episode follows Pemberton and Shearsmith as bumbling burglars attempting an art heist. Their plans unravel when they encounter the homeowners' mid-escalating argument, dragging them into a far more serious situation than intended. It’s a perfect introduction for newcomers to the show’s humor and originality.
- "Cold Comfort" (Season 2, Episode 4): A workplace comedy-turned-psychological thriller, this episode unfolds entirely through CCTV and desktop camera footage. On his first shift at the Comfort Support Line, Andy fields a disturbing call from Chloe, a suicidal teenager. As her calls persist—and his colleagues offer anything but comfort—Andy finds himself unraveling. Its resonant themes and inventive filming style make it one of the series’ most memorable installments.
- "The Harrowing" (Season 1, Episode 6): Considered the scariest episode of the series, this Season 1 finale delivers a classic gothic haunted house tale. Teenage Katy takes a job house-sitting for eccentric, mysterious homeowners, only to find herself in unsettling territory. More straightforward and less experimental than other episodes, it proves that Shearsmith and Pemberton don’t need a gimmick to captivate—just 30 minutes to give you a genuine fright.
With nine complete seasons, it’s an ideal series to sprinkle in between other shows, or to enjoy when you’ve only got an hour to spare—no cliffhanger will pressure you into starting the next episode. Fans of Black Mirror, Alfred Hitchcock Presents, and The Twilight Zone will find plenty to love here.
Marianne — French Horror at Its Most Chilling
Marianne is a French horror series with English subtitles that premiered on Netflix in 2019. Despite a positive reception, it lasted only one eight-episode season, ending on a partial cliffhanger. Creator and director Samuel Bodin (Cobweb, Furies) has said he had plans for a second season that never came to fruition. While some criticize its unlikeable protagonist, uneven pacing, and shift from genuine terror to near black comedy, most agree the first few episodes are frightening enough to watch while peeking through your hands over your eyes.
Confronted by a childhood friend at a book signing for the final installment of her YA horror series—about a girl named Lizzie who battles an evil witch called Marianne—Emma is shaken by tragedy and the return of her childhood nightmares. Drawn back to the small town she once fled, she faces estranged parents and fractured friendships rooted in past traumas, revealed through flashbacks. The witch who haunted her youth is the very entity in her novels, now determined to force her to write again. The demon’s possession of an elderly woman—brilliantly portrayed by Mireille Herbstmeyer—fuels a terrifying first four episodes, while episode five’s flashback to a seance Emma and her friends attempted 15 years earlier delivers perhaps the series’ most chilling moment.
Fans of Stephen King will appreciate Marianne’s heavy influence from his brand of small-town dread, supernatural evil, and flawed but compelling characters. Viewers who enjoyed Channel Zero or The Exorcist will also find plenty to savor in its mix of psychological unease, occult horror, and moments of unrelenting terror.
All of Us Are Dead — High School, Hormones, and the Hungry Undead
When a science teacher’s failed experiment sparks a fast-moving zombie outbreak at South Korea’s Hyosan High School, chaos erupts with Train to Busan-style speed. Adolescent struggles—bullying, social hierarchy, raging hormones—don’t pause for a flesh-eating crisis. The infection begins in the final minutes of the first episode and spreads at a breakneck pace, tearing through students and staff without mercy. And yes—they do not skimp on the gore.
The surviving students, trapped inside with their zombified classmates and teachers, must rely on their own wits to escape, as no rescue from adults is forthcoming. Meanwhile, the military focuses on containing the infection in fictional Hyosan after the first patient is transferred to a nearby hospital. The series evolves from frantic escape attempts to long-term survival strategies, with students tapping into their strengths—but also making the kinds of questionable choices only teenagers could.
Based on the hit South Korean webtoon Now at Our School, All of Us Are Dead premiered on Netflix in January 2022. A second season was announced later that year, but production only began recently, with release expected in 2026. Fans of K-dramas like Kingdom, Squid Game, Happiness, and Sweet Home will find plenty to enjoy, as will viewers drawn to the survival and social commentary elements of Yellowjackets and The Walking Dead. And if you ever thought high school couldn’t get worse—try adding zombies to finals week.