The chant begins with one person in the crowd. Then it multiplies to dozens, hundreds and finally thousands of people screaming the same phrase in unison.
Uh vai morrer.
Translated from Portuguese to English: "You're gonna die."
Go to any mixed martial arts card in Brazil -- including this weekend's UFC 224 in Rio de Janeiro -- and you'll hear it. When a fighter from the home country faces someone from elsewhere, the words will take over the arena as a way for fans to show support for their compatriot and intimidate his or her opposition.
Yancy Medeiros knows this firsthand. "Put it this way ... I wasn't going into Brazil thinking they were going to be cheering for me if I wanted to knock out their countryman," says Medeiros, a Hawaiian who has fought in both Curitiba and Rio. "I was getting middle fingers and everything when I was walking out to the fight. It's good that I felt that prior to the fight, because I knew how to manage my energy. You feel that energy and want to give that back."
Many consider Brazil to be the birthplace of modern mixed martial arts. Royce Gracie, from Rio, used jiu-jitsu to defeat much bigger opponents in the first UFC event in 1993. Flash forward to 2018 and a large percentage of the current UFC and Bellator rosters hails from the South American country. While still expanding in the United States and around the world, MMA is a major phenomenon in Brazil.
"The sport of MMA here has actually grown massively. It's pretty much right there next to soccer," UFC middleweight Kelvin Gastelum, who faces Ronaldo "Jacare" Souza on Saturday night, says. "As soon as I got here, there were at least 15 people asking me for pictures. That was just insane. I've never experienced anything like it. It was a little overwhelming, in a good way. It shows support in fans here. It's next-level stuff."
Before the fight
While competing in Brazil can be like no other MMA experience, there are a few extra challenges. For one, travel is rarely easy. Medeiros, coming from Hawaii, says he had more than 20 hours of flying (Honolulu to Los Angeles, Los Angeles to Sao Paulo, Sao Paulo to Curitiba) for a bout with Francisco Trinaldo in 2016. Former UFC light heavyweight champion Forrest Griffin, who fought in Rio and Natal, had a similar experience, as he needed to fly cross-country to Atlanta or a city in Florida before heading to Brazil. He estimates he spent about 13 hours in the air.
The biggest issue is likely weight cutting. Many fighters spend time in hot baths -- often with Epsom salt -- or saunas to lose as much water weight as possible. Those aren't always easy to find in Brazil.
"We've been at hotels where there haven't been any bath tubs to help you cut weight. You don't get to cut weight that way, and a lot of people rely on it, including myself," Gastelum says. "Sometimes you have to go to a different hotel and rent it out. I've been confronted by those challenges before."
"I fortunately had a good weight cut, but there were definitely things that a lot of the fighters had to adjust to," he says. "They didn't have big tubs, or the hot water didn't work. One time Max and I fought on the same card, and on his floor he didn't have any more hot water to cut weight. He had to come to my room to cut weight. It was just real inconsistent.
"One thing I'll never forget: They have hella small elevators in Brazil," Medeiros says. "I mean hella small. It was super uncomfortable. I'll never forget that."
During the fight
Griffin believes his first fight in Brazil in 2003 changed his entire career. Facing Ebenezer Fontes Braga in Heat FC 1: Genesis, he recalls the crowd being very intense while he was walking to the ring.
"It was a big opportunity for me. Everyone was cheering against me," he says. "I remember getting into the ring and there being a little blood on the canvas. You could smell it. I remember thinking, 'This is awesome. I'm in the right place.'
"The people are fired up, screaming like crazy. This is what I was meant for."
For UFC broadcaster Jon Anik, that type of fandom is what separates fights in Brazil from those in other areas of the world.
"It just really has a special feel," Anik, who has been to the country more than 25 times in his career, says. "Whether it's Brazilian fighters or not, they just have a huge appreciation for the sport. They pack these arenas and deal with the conditions -- whether it's fights starting late or non-air-conditioned venues. They make noise and support the fighters, and they are passionate about it and are knowledgeable about the sport. It's just a festive atmosphere that you don't get every day of the week."
Medeiros says a lot of what makes Brazil unique reminds him of his hometown of Waianae, Hawaii. The people on the island are honored to be from that area and let it be known whenever possible. Brazil is the same way.
"They love their countrymen. They stick fingers at you, yelling all kinds of cuss words in Portuguese. But as a Hawaiian, I have an understanding of pride and can relate to it," Medeiros says. "Yes, it's very empowering to hear someone else say 'F--- you, you're going to die!' But at the same time, you have admiration for it. Maybe not that belligerent or crazy, but that sense of pride for their home? I admire that."
When Gastelum makes his walk to the Octagon for the co-main event on Saturday night, he'll no doubt hear boos. He'll hear "uh vai morrer." But he'll also hear applause and a sign of respect from the fans in attendance.
With the sport so ingrained in the country, the fans know when two competitors are putting it all on the line. Constant action doesn't always equate to a true MMA battle.
"These fans are very knowledgeable, very vocal, very passionate about MMA and fighters," Gastelum says. "It's getting to be where it's just part of the culture now. Not just some spectacle or entertainment they see on TV. This is becoming more and more part of the culture here in Brazil, which is pretty cool.
"If you go look at my social media, a lot of the comments are from Brazilian fans. Not American fans, not Mexican fans, but mainly from Brazilian fans. I have people saying, 'Good luck on the fight. I'm not rooting for you, but good luck.'"