Gu Gu the panda has struck again, mauling someone who jumped a barrier to retrieve a child's toy, in his third attack on a visitor at the Beijing zoo.

A tourist from China's Anhui province went over a 4-foot, 7-inch barrier surrounding the panda's outdoor exercise area Wednesday to retrieve a toy dropped by his 5-year-old son, said a zoo spokeswoman surnamed Gong.

The 240-pound Gu Gu bit the intruder's legs and refused to let go until zookeepers pried his jaws open with tools, said Gong, who would not give her full name as is common among Chinese officials.

The Beijing News identified the man as Zhang Jiao, and quoted tourists as saying Zhang appeared to first look around to check if there were pandas nearby before jumping the barrier.

Gu Gu first made news in 2007 when he bit a drunken tourist who jumped into his pen and tried to hug him. The tourist retaliated by biting the bear in the back. In October, Gu Gu viciously bit a teenager who climbed into his exercise area out of curiosity.

The Beijing News said the latest victim suffered damage to major ligaments and is recovering from surgery.

Pandas, generally considered cute, can nonetheless be violent when provoked or startled. Zoo officials have considered unspecified measures to prevent further incidents.

Police were investigating, and it was not clear yet if Zhang would face criminal charges, Gong said.