A 9-year-old Minnesota girl found a five-legged frog with 23 toes near Stewartville, Minn., according to a report.

Three of the frog's legs appear to be normal, but the fourth has another leg as an offshoot, with three feet attached to it.

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Cori Praska and a friend found the deformed frog in the southeastern part of the state.

This find is disturbing to some experts at the Quarry Hill Nature Center.

"It does concern me and mutations like this shouldn't happen that often," Greg Munson of the Quarry Hill Nature Center said.

Munson says 27 other frogs found by Praska were normal.

Experts say the animals are particularly sensitive to pollutants, which can be absorbed through their skin. Because of that, deformed frogs are considered a sign of environmental problems.

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