Panda bears are seen as cute but can be vicious
A panda at the Beijing zoo has bitten a tourist for the third time in two years, causing leg injuries.
Gu Gu the panda had to have his jaws forced open to free the man, who had jumped in to retrieve his son's toy.
Gu Gu first bit a man in 2007, when a drunken tourist jumped into his pen and tried to hug him, then bit the panda in the back in retaliation.
Gu Gu later bit a teenager who had let curiosity about the panda's pen put him in harm's way.
The latest incident saw the 110kg (240lb) Gu Gu maul the legs of Zhang Jiao.
"The panda bit into the man's right leg, and when he was done with that, he bit the left leg," the Beijing Morning Post reported.
The panda refused to let go until zookeepers pried his jaws open with tools, said a zoo spokeswoman surnamed Gong.
Mr Zhang Jiao of central Anhui province suffered damage to major ligaments and is recovering from surgery.
He may also face criminal charges for entering the panda pen.
Pandas, a national symbol of China, are mythologised as cute and cuddly but can often be violent.
Scientists believe fewer than 2,000 giant pandas live in the wild in China.