The Tsuchinoko ("Child of the mallet") is an unknown snake said to live in the forests of Honshu and Shikoku. They are one of the oldest reported Japanese cryptids, being mentioned in the Kojiki, the earliest surviving literary work in Japan, being over 1,300 years old.
Tsuchinokos are typically described as being two to three feet in length, with mottled brown or black skin, and an orange underside. They also have large eyes, and sometimes fleshy horns, similar to some viper species. The most well-known feature of the tsuchinoko's anatomy is the shape of its body. They are somewhat flat and have a very wide body, except for their short tail.
Some reports of tsuchinokos describe them as venomous. For whatever reason, they're often said to smell like chestnut tree flowers. They are also said to be good swimmers. Tsuchinokos have been reported to vocalize, sometimes making chirping or barking noises.
One of the earliest detailed accounts of the tsuchinoko is featured in Terashima Yoyasu's 1712 encyclopedia Wakan Sansai Zue. In the book, it describes the tsuchinoko as a strange snake that lives deep in the mountains near the Natsuki River. It had a uniformly dark, fat body shaped like a mallet, with a blunt tail.
In Shinano Kisatsuroku, an 1886 book about the geography of the Shanano province (now Nagoya prefecture), it briefly mentions tsuchinokos. It says that they only come out in August and live deep in the mountains.
Recent sightings have also occurred. For instance, in June of 1994, a farmer named Kazuaki Noda was with his wife cutting the grass when they came across a tsuchinoko. He described it as having a body "shaped like a beer bottle" and had an almost tortoise-like head.
On May 21st, 2000, another farmer cutting grass had a similar encounter. He saw the strange creature, which suddenly slithered across his field. Startled, he swung his weed whacker at it. Though the creature was badly injured, it managed to slither away towards a nearby creek. Four days later, 72-year-old Hideko Takahashi came across the dead body of presumably the same tsuchinoko at the creek. He described it as having a long, limbless body, a round face, and was "clearly not a snake." He then buried it.
In the 2000s, an increase of tsuchinoko sightings occurred. On June 15th, 2000, an elderly woman named Mitsuko Arima claimed to have seen a tsuchinoko swimming along a river near her home in Yoshii. She said it was a fat, snake-like creature with a round face and big eyes. When interviewed, she said, "I've lived over 80 years, but I'd never seen anything like that in my life."
There are various theories as to the origin of the tsuchinoko. There is, of course, speculation that it is a real undescribed species of snake. Some have speculated that the tsuchinoko is an unknown species of legless lizard. This is due to the tsuchinoko's more rounded head and serpentine, albeit un-snake-like appearance. Though no legless lizards are thought to inhabit Japan, various distinct populations of lizards have convergently evolved leglessness, so it may not be as unlikely as it seems.
Other theories propose that it may not be an undescribed species, but a misidentified one already known to exist. Some speculate it may be a misidentified tiger keelback or Japanese pit viper that may have eaten a large animal, causing its stomach to appear bloated.
The Tsuchinoko is one of the most widely reported, and inarguably the most famous cryptid in Japan. It is often featured in Japanese pop culture, such as video games, advertisements, and even cereal mascots. Japanese cryptozoologist Naoki Yamaguchi has recorded over 200 different sightings throughout Japan.