Animals Wildlife World's Largest Rodent Shows Up in California, Spurs Viral Internet Craze (Video) By Brian Merchant Writer UC Santa Barbara Brian Merchant is the author of The One Device, editor for OneZero, and is writing a book about Luddites. He lives in Los Angeles. our editorial process Twitter Twitter Brian Merchant Updated October 11, 2018 Migrated Image Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Okay, so if you're on Twitter or read the blogs or pretty much go online at all during the course of the day, you probably encountered the R.O.U.S. meme spreading like wildfire yesterday. A man in Paso Robles, California had spotted and photographed what looked like a massive rat scurrying about in a waste water treatment plant, and posted pictures online of his discovery. The photos quickly went viral. Watch: Inevitably, speculations about the appearance of the chupacabra, the mythical rodent from Mexican lore, were bandied about. No one, it seems, can ever get enough of chupacabras. But it turns out that it was indeed a giant rodent -- the biggest in the world, in fact. Here's the CS Monitor: On July 22, a giant rat (or guinea-pig) called the capybara was seen spending a lazy day in a wastewater treatment plant in Paso Robles, Ca. The capybara is the world's largest rodent, and the California Department of Fish and Game says this one weighs 100 to 120 pounds.It's also quite possible that he or she is something of a local legend. MSNBC recalls numerous capybara-sightings in the area throughout the years, and authorities say the same animal could have been the culprit every time.Authorities believe it was originally a pet that either escaped or was let go. It's not a danger to anyone, and experts say it can lead a perfectly healthy life on its own in the California wilderness. Definitely a fluff story, but fun to see the internet worked up over some unusual wildlife for a change -- and the obvious allusion to Princess Bride's Rodents of Unusual Size probably helped seal the deal.