Denmark’s Caroline Wozniacki (L-R), Canada’s Milos Raonic, Switzerland’s Roger Federer, Australia’s Lleyton Hewitt, Serbia’s Novak Djokovic and Belarus’ Victoria Azarenka pose with characters from Teenage Mutant Ninja Turtles during Kids Tennis Day at Melbourne Park, Australia, on Jan 16. The Australian Open tennis tournament starts on Jan 18.REUTERS