A panda in Qixing Park in southern China has bitten a student who tried to get a hug. The 20 year old said the panda, named Yang Yang, "was so cute and I just wanted to cuddle him. I didn't expect he would attack."
In the same article, another panda attack on a drunk tourist in Beijing is mentioned- the tourist "broke into his enclosure and tried to hug him while he was asleep", only for the panda to bite. The tourist retaliated by biting the bear back in the back. Nice!