In a nutshell:
Kappa were once whispered about with trepidation, their name synonymous with a chilling terror that lurked beneath the water’s surface.
They were the nightmarish specters known for dragging unsuspecting souls to a watery grave and feasting on their vital organs.

Yet, in a twist of fate as mysterious as the creatures themselves, from the 1950s onwards, their dread-inspiring reputation underwent a metamorphosis.
The Kappas, once the personification of fear, started being recast in the collective consciousness as charming, humorous beings, a stark contrast to their once ominous legacy.
What are Kappa?
Kappa, revered as some of Japan’s most renowned yōkai (imaginary beasts), have a pervasive presence, not only in the realm of manga and anime, but also in the more mundane worlds of television commercials and as representative mascots for local governing bodies.
This omnipresence attests to a collective Japanese envisioning of their distinct features and behaviors.
To the modern Japanese observer, Kappa are commonly pictured as child-sized, green, hairless beings.

They sport a peculiar circular dish on their heads, fringed with a distinct growth that bears resemblance to hair, and a beak sharp and pointed like that of a bird, often rendered in a striking yellow.
Reminiscent of turtles, their backs showcase a shell-like structure, and their hands and feet are webbed.
Residing in the aquatic realms of rivers and ponds, Kappa are infamous for ensnaring swimmers by their feet, drawing them to a chilling underwater demise.
Yet, paradoxically, contemporary depictions often render these seemingly horrific entities as lovable, if slightly naughty, cartoon characters.
The Influence of the Edo Period
The prevailing conceptualization of the Kappa, as we know it today, has only taken shape relatively recently, between the 19th and 20th centuries.
This modern representation is a far cry from the creature’s traditional depictions. Even their nomenclature used to vary significantly across different regions.

During the Edo period (1603–1868), they were referred to as Kawatarō or Gataro in the Kamigata region encompassing Kyoto and Osaka.
In the Tōhoku region, they were known as Medochi, Mizushi in Hokuriku, Enkō in Chūgoku and Shikoku, and Hyōsube in Kyūshū.
Prior to the 18th century, Kamigata held the position of being Japan’s cultural hub. Consequently, contemporary documents primarily used the term ‘kawatarō’, acknowledging ‘kappa’ as merely a regional derivative.
However, the 19th century witnessed a profound cultural transformation, largely fueled by the ascendance of woodblock printing, which catapulted Edo (modern-day Tokyo) to an unchallenged preeminence in publishing.
Consequently, ‘kappa’, the variant from Edo, transitioned to the mainstream narrative, mirroring how the Tokyo dialect became the standardized Japanese in the modern era.
The Metamorphosis of Kappa Image
Until the eighteenth century, Kappa were predominantly considered akin to mammals such as monkeys or otters rather than being classified as reptiles or amphibians.
The fifteenth-century lexicon Kagakushū (Collection of Low Studies) elucidates that as otters age, they transform into kawarō, marking the earliest documented reference to kappa.
In a Japanese-Portuguese lexicon compiled by Jesuit missionaries in Nagasaki in 1603, the term ‘kawarō’ for kappa is defined as a monkey-like entity residing in rivers.
However, by the nineteenth century, the portrayal of kappa with turtle shells began to dominate.
Similar to the term ‘kappa’, this transformation can be attributed to the influence of Edo.
Propelled by printed resources, particularly visual mediums like ukiyo-e prints, this depiction, which was previously a minor variant nationwide, soon defined the new norm.
Take, for instance, Katsushika Hokusai, who adhered to Edo conventions in his portrayal of kappa.
In his ‘Hokusai manga’ (Sketches by Hokusai) picture books, he illustrated kappa with pointed beaks and bodies and shells resembling various turtle species.
Other ukiyo-e artists occasionally depicted kappa with green bodies, possibly drawing a link with frogs.
While there is scarcely any evidence of past traditions for green kappa or affiliations with amphibians, their webbed feet and resemblance to the silhouette of young children (except for the head) indicate that some artists may have opted to use frogs as a handy reference for these fantastical beings.
What is important to emphasize here is that the Edo-period ukiyo-e are chiefly responsible for the contemporary perception of kappa as green entities.

The Emergence of Cuter Kappa
During the Edo period, kappa and other yōkai transitioned into characters in illustrated books (kusazōshi) – the precursors to modern-day manga.
They were often presented as humorous entities, with their inherently horrifying nature, manifesting in their propensity to submerge unsuspecting humans, significantly subdued.
However, it wasn’t until the 1950s that these creatures started being depicted as unequivocally endearing. Shimizu Kon’s manga creations, ‘Kappa kawatarō’ and ‘Kappa tengoku’ (Kappa Heaven), triggered a widespread kappa craze due to their immense popularity.
His charming rendition of the aquatic yōkai morphed into a mascot for the annual Tokyo Citizen’s Day on October 1 and featured in commercials promoting snacks and sake.
The characters developed by Shimizu played a crucial role in establishing a ‘kawaii’ (cute) persona for kappa.


The Terrifying Image of Kappa in the Past
Mass media has wrought a transformative metamorphosis on the kappa, transfiguring it into a creature divergent from its terrifying ancestral image.
This particularly concerns the fading of its nightmarish reputation. In the past, kappa were whispered to lurk beneath the surface, their chilling grasp pulling unsuspecting humans, cattle, and horses into the depths of rivers to feast on their inner organs and the mythical shirikodama, a mysterious orb located within the anus.
It was said that they sexually violated women, compelling them to bear their offspring, and they were rumored to have the power to inflict madness or illness upon their victims.

As per folklore, kappa are often depicted as enthusiasts of sumō wrestling, a trait that may initially appear to lend them a quaint charm.

However, this perception is quickly dispelled when it is considered that they reportedly drag defeated human opponents under the water’s surface or inflict other forms of harm upon them.
The Shrines Revered Kappa
Despite the fearsome reputation of these yōkai, there are tales in which they prove beneficial to humans.
One prevalent legend tells of a kappa whose hand was severed for touching a woman inappropriately while she used the toilet. To reclaim its hand, the kappa disclosed the formula for a miraculous medicine.
In a different narrative, a kappa attempting to drag a horse into the water is instead hauled onto land. It is pardoned only after it vows never to endanger the villagers again.
Such tales occasionally include accounts of the creature’s oath, or instances where it is honored as a water kami, a deity of the water.

These narratives draw parallels to Japan’s ancient tales from the divine era, positioning the kappa as a type of nature spirit.
The early Japanese population, awestruck by nature’s force, endeavored to gain some control over its perils by embodying it in the forms of kami or yōkai.
Kappa symbolized the perils of natural water bodies, like rivers, ponds, and the sea, where even the most adept swimmers could drown with a single careless move.
The kappa was conceptualized as a cautionary emblem against such recklessness.
In the present day, “No Swimming” signs often feature illustrations of kappa next to rivers and ponds. Regardless of their endearing portrayal, the message they communicate remains a serious warning.