A child made the disturbing discovery of a zombie knife measuring almost half a meter long under a playground bush. The eight-year-old unearthed the ferocious weapon, set to be outlawed next month, in a Faversham park before alerting his grandfather. They had been litter picking with his nine-year-old brother when he spotted the 40cm long blade with a serrated back edge under shrubs. Describing his disbelief at the discovery on Sunday afternoon, grandfather Ted Wilcox said: “I was shocked and very concerned. It is totally unacceptable. My grandsons and I have been litter picking for years and …