There is a beef between UFC champion Conor McGregor and boxing legend Floyd Mayweather Jr., and the beef is getting pretty big.

Comparisons were drawn between the two after McGregor defeated Eddie Alvarez at UFC 205 at Madison Square Garden on Saturday to win the lightweight belt, becoming the first double champion in the competition’s history.

With the pair not already on the best of terms, Mayweather, in typical Mayweather fashion, called the comparisons “disrespectful.”

He told TMZ: “I didn’t know he was undefeated, I didn’t know he reigned in MMA for 20 years and was undefeated, and was world champion in five different weight classes. That’s something I didn’t know.

“If you say he’s the Floyd Mayweather of MMA, then I’m trying to find out. Has he ever made $300million (£240m) in one night? $100m (£80m) in one night? $70m (£56m) in one night?” he said.

“I’m a legend, a living legend; to the sport of boxing I gave years and years of hard work; there was blood, sweat and tears.

“Conor McGregor can go out there and do what he do, but never compare Conor McGregor to me, it’s a total disrespect.

“Once again, I’m an elephant. Elephants don’t beef with ants, an elephant is so large it doesn’t even see ants.”

McGregor was asked if he had a response to Mayweather’s comments, and told TMZ: “Tell him to say it to my face.”

The head of the UFC, Dana White, admonished Mayweather and told him to respect what McGregor has been able to achieve.

“Conor McGregor, if he touches you, you go to sleep. Floyd puts people to sleep too, with his fighting style, not with his hands,” White said.

“Floyd can say what he wants about Conor, but even other fighters have to respect him. He’s special. Floyd’s never even come close to doing to other fighters what Conor does.”

The two were rumored to be planning a cross-platform fight once, but it never materialized.

“I tried to make the fight happen between me and Conor McGregor,” Mayweather Jnr told in September. “We wasn’t able to make the fight happen, so we must move on.

“I feel honoured to be the biggest name in MMA and in boxing, and I don’t even compete no more.”