These were not the brightest, but nonetheless, despicable.

Plumbing Problem

"Dennis Nilsen. He lived in a London apartment building. The way he disposed of bodies was grinding them up and sending them down the plumbing. Eventually the drains for the building clogged and someone called and complained so a plumber was called to the building. The plumber ended up finding the sewer line for the building clogged with ground human meat."

"Twist: it was Dennis Nilsen who called to complain about the plumbing issue."

– Clcooper423

Dead Giveaway

"'Worst' like really bad at it? Peter Goebbels really wasn't anywhere near sophisticated and quite dumb. On his days off he'd find a woman in a secluded place and then choke them. He was immediately caught because he accidentally left his ID at a crime scene."

– shaka_sulu

Some thought those who have targeted children were the most contemptible.

Gilles de Rais

"Gilles de Montmorency-Laval (Gilles de Rais). Dude killed, assaulted, and ate 100-200 children between 1432 and 1440."

– transzient

"Moon Maniac"

"Albert Fish is disgusting. Read his wiki and it’s baaaaad."

– MontStuart

The Killer Clown

"John wayne gacy legit a serial killer there couldn't be anything worse than this."

– Time_Restaurant_9776

Milwaukee Cannibal

"Jeffery Dahmer for me, he did some truly awful and stomach turning things."

– lonesomeartis

Not The Nurturing Type

"Amelia Dyer. She pretended that she was caring for/adopting out babies from unwed mothers, but really she was just taking the money the mothers provided and killing all the babies. She got away with the scheme for 30 years and she is estimated to have killed up to 400 infants—through neglect/starvation, strangulation, and possibly other means. She just changed names and moved towns when someone got suspicious."

– qwertyuiiop145

Castle Of Terror

"Possibly Elizabeth Báthory? She was a Hungarian noblewoman who lived in the 1500s in a castle and was reputed to have tortured and killed more than 600 young women and girls."

"She was an utterly sadistic creature who thanks to her large wealth & status (which in Medieval feudal Hungaria, pretty much afforded her almost total power over the people in the lands under her care), was able to terrorize the local population unchecked for a very long time. Towards the end, she didn't even bother hiding the bodies (they were simply dumped around the castle to rot in plain sight) but young women in the local area had no power to resist her calls to the castle. The only thing that tripped her up in the end was when she killed a girl she had summoned to her court to sing for her but hadn't realized that the girl actually came from a relatively high status family. Upon their daughter disappearance, it was this noble family who then forced open an investigation at the castle, whereupon the horrifying scale of the psycho noblewoman's years-long killing spree became apparent."

– Creative_Recover

Some thought the methods by which killers committed their unspeakable acts of horror were among the worst

Taking Sight

"Andrei Chikatilo. Reading the dudes wiki pages made me cringe with horror multiple times. Something about stabbing people in the eyes before you kill them is reaaaaal gross to me"

– MonkeyDDeclan

Household Tools Were Weapons Of Choice

"The Tool Box Killers did some absolutely horrific things to their victims as well."

– Greystorms

Lady Killer

"Possibly Elizabeth Báthory? She was a Hungarian noblewoman who lived in the 1500s in a castle and was reputed to have tortured and killed more than 600 young women and girls."

"She was an utterly sadistic creature who thanks to her large wealth & status (which in Medieval feudal Hungaria, pretty much afforded her almost total power over the people in the lands under her care), was able to terrorize the local population unchecked for a very long time. Towards the end, she didn't even bother hiding the bodies (they were simply dumped around the castle to rot in plain sight) but young women in the local area had no power to resist her calls to the castle. The only thing that tripped her up in the end was when she killed a girl she had summoned to her court to sing for her but hadn't realized that the girl actually came from a relatively high status family. Upon their daughter disappearance, it was this noble family who then forced open an investigation at the castle, whereupon the horrifying scale of the psycho noblewoman's years-long killing spree became apparent."

– Creative_Recover

House Of Horrors

"H.H. Holmes. He built a literal murder castle."

– JwSatan

Elusive Malaise

"Cancer. They still haven't caught him."

– Poorly-Drawn-Beagle

For Pure Entertainment

"The Toy Box Killer wasn't the most prolific but he is probably up there with the most terrifying. The way he took his time with his victims and how much he enjoyed it. Most people haven't even heard of him, either."

– Badger_1066

Zodiac Killer

"The dude taunted the police with series of letters Claimed he killed more Made a f*king language that only he would understand and mailed the police Most of the letters aren’t still decoded and so far the ones said to decoded isn’t 100% sure Source: Based on what I’ve seen so I can’t say for sure if he did send the letters"

"But other than that -He hasn’t been caught. -Clean crime scene as he was able to escape swiftly without giving valuable evidence which could lead to his arrest. -Still no definite answer on who the zodiac killer is. Still no solid suspects."

– Scoobys_panacake

The Ripper Of Rostov

"Andrei Chikatilo. Over 200 confirmed victims over 30 years. Avoided Soviet police became he was a government employee and never suspected. This was pre-DNA days. Finally caught, they put him in a cage for his trial. He was sentenced to death."

– otcconan

People glorify sadistic torture scenes in movies.

There's something thrilling about watching a crazed masked killer on the loose on the screen because audiences who love horror films can take comfort in the fact they will come out of the experience with their lives intact.

But the real monsters are not of the Michael Myers and Freddie Krueger variety.

The notorious, real-life killers previously mentioned can outrank any of these boogeymen as "the worst," any day.