The Tama Zoo on the western outskirts of Tokyo staged a drill to train staff what to do in the event of an animal escape.
A staff member dressed as a snow leopard "escaped its enclosure" and knocked over a member of staff. Other zoo employees chased after it with nets, poles and tranquilliser darts.
The zoo said the drill was designed to simulate animals escaping after a disaster like an earthquake. "We focused on making this drill as realistic as possible. One of our staff being knocked down, injured and then being knocked unconscious and going into cardiac arrest was a part of that," Tama zoological park director, Yutaka Fukada, explained.
Zoo visitors watching the event had trouble taking the rather fluffy leopard seriously. "It's not scary at all," three-year-old Toki Yokomatsu said.
"He's not scary at all, but chasing him down the hill must have been quite a bit of work," said three-year-old Sora Ichikawa.
Not scaring the children was a disappointment for the man in the snow leopard costume. "Personally I feel I did my best but it didn't work for kids. I'm a bit disappointed," Toshiya Nomura said.
A total of 70 staff members took part in the exercise as well as police and local emergency workers who finally apprehended the "leopard" on the loose.
Tokyo's Tama and Ueno Zoos take it in turns to stage these drills every February. Previous "escaped animals" have included a couple of gorillas, a realistic rhinoceros, a fairly realistic zebra, and a decidedly fake zebra.