Warning: Disturbing and graphic content ahead.
1. France — Marcel Petiot, a medical doctor and serial killer convicted of 26 murders (though suspected of killing as many as 200 victims), during the 1940s. The majority of his victims were Jewish refugees fleeing France during the Nazi occupation.
2. Brazil — Pedro Rodrigues Filho, aka "Killer Petey" (among many other monikers), who was charged with 71 counts of murder, but claimed to have killed over 100 drug dealers, rapists, and murderers.
3. Denmark — Dagmar Overbye, a serial killer who worked as a child caretaker and murdered somewhere between 9 and 25 children (including one of her own) from 1913–1920.
4. Egypt — Gaddafi Farag, aka the "Giza Butcher," who violently killed at least four people from 2015 to 2017 (including his wife) in an attempt to cover up fraud. A true crime TV series about Farag's exploits was recently released on Shahid TV and became a huge hit.
5. Mexico — Juana Barraza, aka the "Little Old Lady Killer," a former professional wrestler who reportedly killed between 42–48 elderly women from the late '90s until the mid '00s — although the true number is unknown.
6. Scotland — "Bible John," an unidentified serial killer who's believed to have murdered three women between 1968 and 1969 in Glasgow. The killer was dubbed "Bible John" because, according to a witness, he would quote Bible scripture.
7. South Korea — Yoo Young-chul, aka the "Raincoat Killer," a convicted serial killer and self-confessed cannibal who murdered (at least) 20 people in and around Seoul from 2003–2004. When asked about his motive, he told the media, "Women shouldn't be sluts, and the rich should know what they've done."
8. England — Harold Shipman, a doctor who became known as one of the most prolific serial killers in modern history and was active from the 1970s to 1990s. Although he was convicted of only 15 murders, it is believed he actually had as many as 250 victims. Shipman would kill his victims, who were mostly elderly patients, by giving lethal doses of drugs.
9. Germany — Niels Högel, a former nurse and convicted serial killer responsible for at least 85 murders from 2000–2005. Since his conviction, estimates of his victim count have been as high as 300, and he is considered "Germany’s deadliest post-war serial killer."
10. Australia — John Justin Bunting, Robert Joe Wagner, and James Vlassakis, who were convicted of killing 11 people from 1992–1999 in what became known as the "bodies-in-the-barrels" serial killings. The victims' bodies were found in barrels of acid in an abandoned bank vault in the small town of Snowtown, near Adelaide. It was reported that the smell inside the vault was so bad "that police needed breathing gear."
11. Japan — Tsutomu Miyazaki, aka the "Otaku Murderer," a serial killer who was responsible for the abduction and murder of four young girls from August 1988–June 1989. The gruesomeness of his crimes included the fact he dismembered and molested their corpses as well as engaged in cannibalism.
12. Canada — The "Highway of Tears" killer (or killers), which refers to a 450-mile corridor of Highway 16 in British Columbia where many Indigenous women have gone missing and/or been murdered since at least 1986.
13. Turkey — Yavuz Yapıcıoğlu, aka the "Screwdriver Killer," who, as the name suggests, used a screwdriver to kill his victims. Yapıcıoğlu is considered one of the most prolific serial killers in Turkish history, having killed at least 18 people from 1994–2002.
14. India — The "Stoneman," an unknown serial killer who murdered at least 26 people experiencing homelessness, while they were asleep, in the mid to late '80s. The moniker comes from the fact that the killer would crush the victims' heads with a large stone.
15. Colombia — Luis Garavito, aka "La Bestia" ("The Beast"), a serial killer, sex offender, and necrophile who confessed to the violent murders of at least 140 minors, mainly young men and boys, during the '90s.
16. Belgium — The "Butcher of Mons," an unidentified serial killer who is believed to have killed at least six women in or around Mons between January 1996 and July 1997. The victims' bodies were dismembered with "anatomical expertise," and various body parts were left in "neatly tied" bags.
17. Italy — The "Monster of Florence," an Italian serial killer (or killers) active in the areas in and around Florence from 1968–1985. Their killings were so shocking they inspired the creation of the character Hannibal Lecter.
18. Namibia — The "B1 Butcher," a serial killer who murdered at least five women between 2005–2007 and was never identified. The killer was dubbed the "B1 Butcher" by the media because the victims' remains were found near the Namibian National Road B1.
19. Russia — Mikhail Popkov, aka the "Werewolf," a former police officer and serial killer, rapist, and necrophile who murdered at least 78 girls and women from 1992–2010 in different parts of Russia.
20. China — Yang Xinhai, aka the "Monster Killer," a serial killer who confessed to murdering 67 people from 1999–2003. Allegedly, his motivation for the killings was "revenge against society," after a breakup.
21. Argentina — Carlos Eduardo Robledo Puch, aka "The Angel of Death," a convicted serial killer who came from a wealthy family and murdered 11 people in the greater Buenos Aires area in the early 1970s.
