"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.
"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," said Tyson.
Mayweather hasn't fought since defeating Andre Berto in September 2015 leaving his career record at a staggering 49-0, however is in talks with MMA superstar Conor McGregor to hold a superfight later this year.