It has been revealed this week that Mike Tyson could bring grown men to tears during sparring sessions, even if they were using protective equipment like head guards and body armour.
Former boxer Joe Egan has revealed what it was like to share the squared circle with Iron Mike, if only for sparring.
Tyson, now 53, is reportedly considering a return to the ring for a fight to raise money for charity, but back in his prime days, he was one lethal animal... even in sparring.
Back in 1986, aged only 20, Mike Tyson became the youngest heavyweight champion in history with a second-round TKO over Trevor Berbick for the WBC heavyweight belt.
Within a year, Tyson had picked up the WBA title by beating James Smith and the IBF belt against Tony Tucker in his 31st fight.
Tyson would claim the lineal heavyweight titles and The Ring belt a year later before a shock defeat to Buster Douglas in February 1990.
As he prepares for a reported comeback 33 years later, Egan has revealed that fighters were not allowed to step into the ring with him unless they wore a head guard.
His sparring partners were also made to wear bigger gloves and even body armour.
Egan stated, as per The Sun: "Against ferocious puncher like Mike, you've got to work on your defence.
"When he connected with a flurry of solid punches, you couldn't remember what hit you, just the pain - that's what you remembered, the pain.
"And the swelling came after. When sparring Mike you had to wear a head guard, you couldn't spar him without a head guard.
"And also you wore big gloves, and sometimes body armour to protect your ribcage because his blows were just so brutal.
"He had the capacity to snap a man. It was like he could break bones with punches.
"Believe you me, he could fight and hurt you real bad in the ring - even make you cry.
"He hurt me and made me cry many times. Yes, he made grown men cry at the camp.
"But after sparring sessions Mike would embrace his sparring partners. His sparring partners helped him to get to the top of his chosen sport.
"There are only a few people - including Lennon Lewis, Evander Holyfield and myself - who have been in the ring with Mike at their peak who he never actually put on the floor."
Tyson ended his career with 50 wins, including 44 knockouts and only six defeats. His final professional fight came in 2005 in a defeat to Kevin McBride in Washington D.C.
His last marquee bout was a clash with former undisputed champion Lennox Lewis, which he lost after an eighth-round stoppage in 2002.