Fangs pierced Leah Prudhomme's legs as she swam across the deep, dark rum-colored northern Minnesota lake. It could be anything, she thought -- muskrats, beavers, maybe a muskie. But it didn't let up.
In the middle of Island Lake near Duluth, the triathlete struggled as the animal sunk its needle-sharp teeth into her legs, feet and back, leaving 25 bite marks, some 2 inches deep.
"It just kept coming after me," said Prudhomme, 33, of Anoka. "You never knew where it was going to bite next."
In between peppering her with puncture marks, the animal's head popped up a few feet away. That's when Prudhomme noticed its distinctive long tapered tail, small beady eyes and gray head. An otter.
"I couldn't believe Duluth had an otter," she said Saturday before getting more rabies shots, her swollen ankles and bite marks still healing three days after the incident.
The rare lake attack baffled conservation experts and doctors, who could only surmise that the atypically aggressive otter had rabies or was a mother protecting young pups.
"I've never seen or heard of it before," said Mike Scott, a conservation officer with the Minnesota Department of Natural Resources in Duluth. "We've got otters everywhere ... lakes, streams. Most times, [swimmers] wouldn't even know it. Otters usually stay away."
As a Duluth native growing up on Pike Lake, Prudhomme was familiar with the trails, water and wildlife, and had swam Island Lake several times. Last Wednesday, she was visiting her father on the lake and left with a friend for an eight-mile road run and half-mile swim in preparation for her second Ironman Triathlon. Despite the sunny, 90-degree day, they donned wet suits and goggles over swimsuits before diving into the dark lake.