AP reported from Paraty, in southern Brazil, where Carnival revelers typically head to parties in colorful, skimpy outfits and splatter glitter—but this year’s festivities in and around the town’s old historic areas turned on something else: mud. Instead of adding shine, participants draped themselves in a gray sludge and rolled in the silty shallows of a beach, forming what AP described as a unified mass.

Among the revelers, Charles Garcia Pessoa, a 37-year-old entrepreneur, described the mud party as a social equalizer. He said the event leads people to feel “kind of the same (…), those who have money and those who don’t,” adding that “everyone comes here to jump into the mud.” Under a blazing sun, the mud-covered crowd danced, shouted, and marched along the sand with musicians, AP reported.

AP said the partygoers also performed a chant, including “Uga! Uga!” as they moved through the beach setting. In the framing of the tradition, the mud does not function as a prop dressing for a moment; participants continue to treat it as the central shared element of identity through the gathering.

The origins of the mud party trace back to 1986, according to Paraty’s tourism site as described by AP. The site says that friends who were playing in the mangroves at Jabaquara Beach realized they were no longer recognizable and then went strolling into the city’s historic center, causing a stir.

AP reported that the next year, according to the same tourism site, a group lathered themselves with mud to present themselves as a prehistoric tribe for Carnival. The site said they carried skulls, vines and bones as they uttered chants, and that the mud party was born from that shift into a more staged, theme-based procession.

Over time, the mud party became a more widely known tradition associated with Paraty’s Carnival season, drawing visitors beyond Brazil, AP reported. Matt Bloomfield, a New Zealander who runs a film festival, said he decided to come after seeing coverage of last year’s event.

Bloomfield described the mud party as a different kind of creativity within Carnival. He said: “Everyone’s being so creative, you see people around decorating themselves with leaves,” and he added, “It’s a great alternate version of Carnival.”