Sonny Bill Williams
Next we come to Williams, notable for his physical prowess in more than one sport. A professional dual-code rugby player by trade, the New Zealand native has also turned his hand to boxing in the past.
Currently playing for the Sydney Roosters in Australia's National Rugby League, Bill Williams fought at heavyweight on six separate occasions between 2009-2013.
Making his fighting debut against Garry Gurr, he went on to leave the sport undefeated having won the NZPBA heavyweight and WBA international heavyweight titles.
Whether it's in the ring, on the rugby field or in the gym, Bill Williams - who won the union World Cup back in 2011 - is not a man to be crossed.