Kangaroos are usually dodgy animals and, as they are vegetarians albeit with gladiator legs for Sparta Kicks, would not attack humans because animals normally only attack because they need food or out of self defense.
Despite their peaceful appearance they are formidable fighters. Most problems probably originate from people feeding them so they come to expect food and get grumpy when they don't get it. Sometimes drought conditions bring them into towns where there is still water and green grass, like sometimes happens in Canberra. There are a few recorded kangaroo attacks, though we have been able too find only human death by roo attack which occurred in New South Wales in 1936 where a hunter was killed when he tried to rescue his two dogs from a fight with a kangaroo.
New research by PhD student Guy Ballard shows more than triple the expected number of kangaroo attacks between South Grafton and Coffs Harbour on the New South Wale North Coast.
Prompted by two kangaroo attacks on children in Grafton in 1999 and 2002, his research over the past two years has since been extended. He said they had thought there would be three to five attacks in the past two years but there's already been 15 to 20 reports.
kangaroo attack
Arthur's Creek, Victoria, November 2009
49 Year old Chris Rickard was walking around his property together with his dog, a blue heeler named Rocky.
They stumbled upon a sleeping kangaroo, who woke up and tried to get away, chased by the dog Rocky. The kangaroo them jumped in to the water and the dog followed. In a self defence move typical for kangaroos the kangaroo grabbed the dog with its front paws and held it under water to drown it. By now Chris had caught up with them and leapt into the water too to save his dog from the five foot roo, but the roo was not giving up the dog just like that and ripped in to Chris too. He received a big gash on his forehead and several deep gashes on his abdomen and chest while he was under water trying to pull his half drowned dog away from the roo and make his way back to shallower water, the roo only finally backed off a bit when Chris managed to elbow it in the throat. During an interview in the local hospital he said that he didn't think he'd ever be able to watch Skippy on TV again.