Born in Brisbane, Australia, Cullimore moved to Auckland when he was 7 after his father died, settling in Northland.
Cullimore then moved to Australia and played lower grades for the Illawarra Steelers and a brief stint with Manly Sea Eagles.
[3][2] He was also selected to go to the 2010 Vancouver Winter Olympics with the Australian bobsleigh team after a successful North American training camp.
[4] Cullimore then trained and fought as a mixed martial arts fighter turning pro with a 3–1 record.
[5] He later trained in natural body building, placing 3rd at the Australian Nationals ANB & International Natural Bodybuilding Association heavyweight divisions and appeared in the Nation's top hit TV show Australian Ninja Warrior in seasons 1 and 2, making the semi-finals.