While most Pokemon are just technicolor merchandise fodder and some are literally just actual animals, there are a disturbing amount of them that are rooted in folklore and spiritual iconography.
Now, the thing about ancient legends and folk tales is that they weren't created with an ESRB rating in mind, so while these Pokemon are free to be sassy and adorable, their origins harken back to a much darker age. Some of these creatures would even make the Brothers Grimm say "yeesh, tone it down a little". Here's 14 pocket monsters based on actual ancient terrors that have survived through the ages.
1. Mawile is based on a story about how you shouldn't starve your wife.
Where did Game Freak get the idea for a magical version of Japan swarming with bizarre supernatural monsters? From Japan itself. The country's folklore is infested with "yokai", creepy crawly monsters that come in hundreds of sizes and shapes. One popular yokai story is of "Futakuchi-onna" or "the two-mouthed woman". Once upon a time, a miserly farmer was overjoyed with his new wife because she miraculously never needed to eat, saving him a bunch of money. However, as the weeks went on he noticed that his grain supplies were getting dangerously low. It wasn't until one horrifying night that he awoke to find his wife asleep, but a second mouth on the back of her head was voraciously devouring his food stores. Tendrils of hair continuosly fed the mouth more and more rice, eating him out of house and home. Mawile is absolutely a reference to this story, sporting a demure gaze and one nightmarish mullet.
2. A horde of Sabeleyes once terrorized a family in Kentucky
One of the most bizarre supernatural encounters ever reported was 1955's "Hopkinsville Goblin case" in which a rural farmhouse was supposedly invaded by a pack of 3-foot-tall aliens. Naturally, since the alleged monsters chose to appear in Kentucky, they were PROMPTLY and REPEATEDLY shot on sight. According to "eyewitness" accounts, the playful yet menacing creatures had small atrophied legs and bright glowing eyes, bullets seemed to bounce off their bodies, and they moved with an erratic swaying motion. There's a small but rabid "cryptid" otaku subculture in Japan, so it's very likely that Sableye's unique physicality was inspired by these creatures.