Daniel Radcliffe debuted his first muggle role since being cast as Harry Potter at the DGA premiere of “December Boys” on Thursday.“I was nervous about being with a whole new film crew and that they’d expect me to be some sort of spoiled brat,” Radcliffe said. The young actor also worried about nailing an Australian accent for his latest pic. “It’s very easy to make an accent a caricature,” he said. “I didn’t want to sound like Dick Van Dyke in ‘Mary Poppins.'” Director Rod Hardy wasn’t apprehensive about casting such a familiar face. “Daniel has a quality and a depth beyond his years, and that’s what the character needed,” the helmer said.