(Facebook/Paulo Henrique Borrachinha)

An Ultimate Fighting Championship athlete has threatened to beat up a transgender competitor in order to “protect women”.

Paulo Costa, a professional mixed martial (MMA) artist, said it “can’t be accepted” that Fallon Fox, who recently transitioned, would be allowed to fight in the women’s league.

In a video posted on Facebook, the Brazilian fighter – who is 6′ 1″ and 185 pounds – constantly misgendered Fox while talking about how much he would enjoy attacking her.

Fox was forced to come out in 2013 after a reporter called her with details about her past.

In Costa’s post, entitled “My video about the nonsense that Follon [sic] Fox, MMA fighter has done,” the fighter ridicules and abuses Fox.

He tells his 57,000 followers: “I’m making myself available to fight him for free, just so I can beat him up.

“I wouldn’t even need much time. Just a few minutes.”

Continuing his rant about the American athlete, Costa, 26, said: “He was born a man, and he is a man, even though he calls himself a transsexual.

“It’s absurd cowardice, not only by him, but also by the promoters of any event that has accepted this kind of absurdity.

“He has simply annihilated the girls who have fought against him.”

He added: “They were slaughtered, they put their lives at risk, they put their physical integrity at risk.

“I don’t want to get into his choice, to be transsexual or not, homosexual or not.

“What happens here is that a man is fighting against girls, against women, as if he were one.

“This is absurd, and it can’t be accepted.”

Fox, who was inducted into the National Gay and Lesbian Sports Hall of Fame in 2014, has faced transphobia in the sport before.

Soon after she came out as trans, MMA champion Ronda Rousey refused to fight Fox.

Rousey said Fox had “an unfair advantage.”

She added: “I feel like if you go through puberty as a man it’s something that you can’t really reverse.

“You can’t just reverse that, there’s no undo button on that.”

Fox destroyed these claims in an interview, pointing out that “nobody has come forward with any verifiable evidence showing that transgender women have a competitive advantage over their peers in sports.”

Costa’s nickname is The Eraser – hopefully his hateful views will eventually be erased from sport.