American Horror Story is one of the most terrifying shows on television, with creator Ryan Murphy crafting characters and situations that are beyond frightening.
Sometimes, the creepy characters aren't totally based on fiction. Throughout the show's six seasons, the creation of several characters were influenced by real life serial killers.
Some took direct elements from their real-life counterparts, and some were fictionalized versions of the historical characters.
Scroll through to see which characters took their murderous tendencies from actual psychopaths.
Dr. Oliver Thredson (Ed Gein)
In AHS's Asylum season, one of the main antagonists was Dr. Oliver Thredson, played by Zachary Quinto. He started out as a mild-mannered therapist for Briarcliff, but his real identity as a serial killer surfaced when he became obssessed with Lana Winters (Sarah Paulson).
He is loosely based on serial killer Ed Gein. Gein was arrested and found insane after authorities discovered numerous body parts around his house, some of which were fashioned into masks and furniture.
Thredson shares this fascination, turning his victims' faces into masks and becoming the serial killer known as "Bloodyface."
Madame Delphine LaLaurie
Kathy Bates joined AHS in the Coven role of Madame Delphine LaLaurie, who was based on the historical figure of the same name.
LaLaurie tortured slaves in her New Orleans estate using nefarious devices such as spiked collars. Her methods often resulted in fatal injuries.
In the series, LaLaurie gets cursed and buried underground for eternity, but in real life, she got off easy for her crimes. When her crimes were discovered, an angry mob formed and tore her estate apart. During the madness, LaLaurie fled and went to France, where she lived the remainder of her life.
Twisty the Clown (John Wayne Gacy)
Freak Show's Twisty the Clown has a presence in Cult, but his original terrifying spree of murders was inspired by John Wayne Gacy.
Gacy was known as "The Clown Killer" due to his job as a clown at children's birthday parties. He killed at 33 teenage boys and buried most in the crawl space of his house.
To make the Gacy-Twisty connection even more interesting, the actor behind Twisty, John Carroll Lynch, portrays the ghost of Gacy during a spooky Hotel scene.
James Patrick March (H.H. Holmes)
James Patrick March (Evan Peters) owned the Hotel Cortez, the main setting for Hotel, and constructed it as the perfect device to murder visitors and dispose of their remains.
This is directly inspired by H.H. Holmes, a serial killer who outfitted a hotel he built into what was virtually a "death house." He allegedly rigged the site up with various booby traps and gas chambers in order to kill unsuspecting victims.
Before his execution, he had confessed to 27 murders, but the real number has been disputed as being both higher and lower.
"The Countess" Elizabeth Johnson (Elizabeth Báthory)
Another main character in Hotel was Lady Gaga's "The Countess" Elizabeth Johnson, who had vampiric tendencies.
She's based on Elizabeth Báthory, who holds the Guinness World Record for being the most prolific female murderer. Also known as "Countess Dracula," Báthory was accused of the deaths of up to 650 young women between 1585 and 1609.
The vampire connection dates back to a legend that Báthory killed all the young women to drink or bathe in their blood to retain her youth.