The 46-year-old children's entertainer and his 31-year-old fitness trainer partner Hannaford — will also compete alongside last year's entrant The Bachelor's Tim Robards.
“We thought it would be a really fun challenge to get involved in,” Hannaford told The Daily Telegraph.
“We love doing anything together that involves being active and being healthy; it’s how we like to spend our time,” she continued.
Hannaford is no stranger to the small screen as she once travelled with The Wiggles for four-and-a-half years as Dorothy The Dinosaur before resigning in 2014.
Ninja Warrior is back on TV this Sunday on Channel 9.
This week on WHO’s fun TV podcast, Binge List, Matt, Clare and Gavin name their top 5 shows of 2018 so far, their biggest disappointments, their favourite Aussie dramas, and the best of reality TV. They also cast a surprising spotlight on some shows you thought were long gone. Subscribe on iTunes: http://po.st/syE3JF or OMNY: http://po.st/IlEcNa