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. This includes the time a farmer found a capybara stealing his horse’s food and chased it off with a shotgun.

But the capybara is no ‘white whale.’ Life in the wild is tough on the creature and can even reduce its lifespan from 8 years to 4, reports FOX news.

If that’s the case, then what effect would a swim in the sewage at Paso Robles have on the animal? The wastewater treatment plant’s website lays out the steps used to clean water before releasing it into the Salinas River, and these include aerating the water, passing it over “roughing filters,” and removing ammonia, which can be “toxic to some forms of aquatic life.”

A local television station interviewed treatment plant workers about what they saw.

Had the capybara not so carefully chosen his entry point, this could have been a deadly obstacle course as well as a poisonous dip. But the mysterious crusader was lucky enough, or crafty enough, to survive the sewage treatment plant and disappear into the river.