The bloody ambush took place in Hamburg's Hagenbeck zoo early last Saturday morning. A cleaner was busy scrubbing benches when she heard a rustling in the bushes next to her, the regional paper Express reported. Unconcerned, she continued until the 1.80 metre-long otter poked its head out of the foliage.
On seeing the animal, the unnamed 56-year-old screamed and tried to run away but fell over - only to be pounced upon by the otter. It bit her arms and legs so severely that she has been hospitalised.
A nearby zoo keeper and an assistant heard her screams and came running, only to be leapt on by the otter as well. They wrestled it to the ground and bound it up, enduring several bites in the process. The zoo keeper is also in hospital with minor injuries.
One of the cleaning lady's arms is so badly injured that she may never regain full use of it, the paper said.
As well as being monitored for possible blood poisoning, she was put into an artificial coma several times since Saturday.
“We have no idea how the giant otter escaped,” zoo spokeswoman Eveline Düstersiek told The Local. “Somehow it must have pushed a hole through the fence, which is strange because the fence is metal.”
Düstersiek said that they did not know which of the zoo's two otters had attacked the woman, but it was either Beni - the mother of the enclosure's otter kits, or her mate Marku.
“Giant otters may look cuddly but they are wild animals and can be dangerous,” she added.