Floyd Mayweather has slammed comparisons with Conor McGregor as "disrespectful" - and the American former boxing champion also questioned his rival's achievements in UFC.
McGregor picked apart Eddie Alvarez at will at Madison Square Garden on Sunday to become the first dual-weight world champion in UFC history.
But Mayweather, the boxing star who has previously been linked with a blockbuster fight against the Irishman, believes the two shouldn't be compared.
Speaking to TMZ, he said: "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 US$300million in one night? $100m in one night? $70m in one night?
"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."
Mayweather, speaking in September, revealed he almost came out of retirement to fight UFC superstar McGregor.
The 39-year-old retired from boxing in September 2015 but was recently considering a bout with McGregor.
"I tried to make the fight happen between me and Conor McGregor," Mayweather told FightHype.com. "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."
But Mark Henry, Alvarez's coach, believes McGregor would prove to be the winner should the two step into the ring together.
Speaking to SiriusXM, he said: "Before this fight, I would highly doubt him fighting Mayweather, but man I think this dude can figure out Mayweather. I don't know if it went [long], but I could easily see him knocking anybody man. Like I said, it's a Babe Ruth swing, there's so many things you need to make it work.
"If you lean forward too much, you don't turn your hips at the right time.. and also his range, he knows his range so well. A punch can be an inch... less than that, it can be a centimetre and he won't pull his head back at times because he knows it's not going to hit.
"He'll slide back his head and counter, but if you don't slide back your head the [counter] can come faster, so there are times he won't slide back his head because he knows it's not going to hit him. I can go even farther, that four punch combination he used to finish off Eddie, he knew where his head was going to be on all four moves, he knows ahead of time where you're going to be.
"What he does is just incredible."