A giant South American rodent weighing at least 45kgs was spotted at a waste-water treatment facility in California recently before disappearing in the brush, according to a wildlife official.
The animal, which was identified as a capybara, is the world's largest rodent and feeds on vegetation.
"If you think a giant guinea pig is cute, then you probably would like it," said Todd Tognazzini, of the California Department of Fish and Game.
The capybara is believed to be an escaped pet, Mr Tognazzini said. It was last seen about two weeks ago at a waste-water treatment facility in Paso Robles, 281km northwest of Los Angeles, he said.
An employee at the plant took photos of the animal as it crawled out of a pond.
The capybara's South American habitat ranges from Panama to northeast Argentina, east of the Andes, according to a description on the website of the San Francisco Zoo.
The animal spotted near the Salinas River and a hot spring, a watery habitat that in some ways resembles the regions where capybaras live in South America, Mr Tognazzini said.
A capybara can hold its breath under water for up to five minutes, and the animal spends much of its roughly four-year lifespan near the water, he said.
The latest spotting of the capybara comes two years after another sighting of the animal a mile away.
Officials believe it was the same animal last seen at the waste-water treatment facility in Paso Robles, and that there are no other capybaras in the area.
In California, the capybara cannot be held as a pet without a special permit. But that does not mean that some people do not keep them as illegal pets.
"The Internet is fraught with examples of people scratching them on the belly and thinking they're cute and making pets of them," Mr Tognazzini said. The California Department of Fish and Game do not view the animal as dangerous.
Reuters