This is the Haka, an ancient war dance from the fierce Maori tribes of New Zealand, now a football ritual in Texas, CBS News correspondent Hari Sreenivasan reports.
"It helps me a lot to get pumped up," said player Numi Lolohea. "To get motivated to get into the game."
"If you gonna do it you got to be serious," said Mao Leota, another player. "[Its] about getting ready for war."
You gotta get ready for war?
"Yes sir," Leota said.
Polynesian players introduced the Haka two years ago. Trinity won the state championship.
They're still dancing and making bruising hits, and beautiful catches. The announcer might say: "Touchdown, Number 84! Tuomoepa!"
That tongue twister is a Tongan last name.
Number 84's mom, Martha, is convinced the Haka has something to do with it.
"Oh yeah, very, he was very shy at first," she said.
On the field the Haka dance is a source of inspiration for one of the best high school football teams in Texas. Off the field it's a source of pride for a tight-knit community.
From their tiny Polynesian homeland, thousands of Tongans have moved to Texas to take advantage of airline jobs at Dallas-Fort Worth airport - and the flight privileges home that come with them.
So many Tongans that they have their own television program. The Haka is a point of pride, a reassuring symbol that they aren't on the sidelines anymore.
"A reassurance from the outside world that we are part of this community - reassurance that they accept us as we are," said Ilaiasi Ofa of the Voice of Tonga show.
In New Zealand, the All Blacks rugby team has been doing the dance for decades.
College teams from Hawaii to Utah fire up fans with their own versiona.
And on YouTube, there's even a team of gingerbread men doing the Haka as a commercial for a New Zealand bakery.
No matter who's doing it: It's all out.
Sreenivasan asked one player: "you went hoarse doing it?"
"Yeah, I'm surprised I didn't pull a muscle!" one player said.
It just may become the new Friday night lights battle cry.