Mike Tyson once took a swing at Floyd Mayweather during official ceremony

Mike Tyson has never been one to hold back when speaking about Floyd Mayweather.

In fact, he once claimed that a prime version of himself would kick Mayweather's "a**e" in a street fight.

The former heavyweight champion, who will go down as one of the all-time greats, also criticised 'Money' for believing he was better than Muhammed Ali ever was.

"He's very delusional," Tyson said. "Listen, if he was anywhere near that realm of great as Muhammad Ali, he'd be able to take his kids to school by himself.

"OK, he can't take his kids to school by himself, and he's talking about he's great? Greatness is not guarding yourself from the people. 'It's being accepted by the people. He can't take his kids alone to school by himself.

"He's a little scared man. He's a very small, scared man."

Tyson and Mayweather's well-documented feud has often produced entertaining snippets and for many, a moment in 2015 sticks out as one of the more memorable.

It all went down when the pair bumped into each other at a WBC convention at the Mirage Hotel and Casino in Las Vegas.

Mayweather, who was the WBC welterweight and junior middleweight champion at the time, shook hands with those on stage when 'The Baddest Man on the Planet' entered the room.

Tyson soon approached 'Money' and pretended to throw one of those famous right hands before walking away with a smirk on his face.

To his credit, Mayweather barely even flinched. In fact, he embraced Tyson while wearing a huge smile on his face.

Of course, this isn't the only eyebrow raising incident involving Tyson and Mayweather.

When 'Iron Mike' was asked about a hypothetical street fight with 'Pretty Boy' in his prime, he told GQ: "[I would] kick Floyd's a**e... there wouldn't even be no match."

But the former undisputed champ would later put his rivalry with Mayweather to one side when he suggested that he'd lose in a boxing fight if he were the same size as him.

He admitted: "[If] I was his size in the ring, he would outpoint me."

Mayweather, who boasts an unbeaten record of 50-0, once claimed that he was the best boxer in history and rated himself higher than the likes of Muhammad Ali and Tyson.