TOKYO >> A mythical, mermaidlike creature that prophesizes harvests and epidemics became a symbol of national unity this year in the face of COVID-19.

Known as “amabie,” the creature is said to have long hair, a duck bill, three legs and scales. It is a “yokai,” a supernatural monster of Japanese legends and folklore.

Images of amabie inundated social media this year and were used in countless ads and on merchandise; it was even a mascot for the health ministry’s public-safety campaign.

In fact, “amabie” was a nominee for 2020’s Buzzword of the Year.

“I don’t think there has ever been a yokai, especially one as arcane as amabie, that has permeated popular culture to this extent,” said amabie expert Eishun Nagano.

The only record of amabie is a “kawaraban,” or woodblock- printed news sheet from the late Edo Period (1603-1868), preserved at the Kyoto University Library. The print from 1846 reports an official being sent to investigate rumors of an unidentified glowing object appearing nightly in the water off Higo province, now Kumamoto Prefecture.

When the official arrived, amabie emerged and foretold plentiful harvests — but also widespread disease. The creature urged him to sketch a picture of its likeness and share it. Drawings of amabie are said to defend against illness.

This year, artwork of amabie were featured on everything from apparel and amulets to labels for craft beer.

“The economic impact of the amabie boom is difficult to calculate,” said Mayuko Kono, chief research officer at JTB Tourism Research & Consulting Co.

Amabie images likely flooded the market because there is no trademark, she said. But companies were quick in attempting to do claim one.

Advertising giant Dentsu Inc. retracted a trademark application in July after facing fierce backlash. But 17 applications remain pending from a range of businesses, including a confectionery and a religious corporation.

From influenza and dysentery to smallpox and measles, Japan has been hit by numerous epidemics over the course of its history. Each time calamity struck, religion and folk beliefs offered comfort. This time, hope came in the form of a three-legged creature.

“I believe amabie reflects people’s desire to offer positivity in the face of an invisible threat,” Kono said.