Testicle-Eating Fish Found in Illinois Lake: “Huge Monster’ Washes Up on Shore Near Chicago [VIDEO]

An Illinois fisherman got much more than he bargained for when a mysterious fish he found washed up in his backyard earlier this week turned out to be a tropical fish known for mistaking human testicles for food.

Jim DePersia, a Chicago retiree whose home sits on the shore of Cedar Lake in Illinois, found the dead fish in his backyard when it washed up on shore, and thought he had found a regular piranha. The fish, which tipped the scales at seven pounds and measured 20 inches long, was actually a pacu.

"As I came up and looked at it, I thought I knew my fish and this is a huge monster," he told CBS News Chicago.

The Pacu, a cousin of the piranha, is known to mistake human testicle for tree nuts as a staple of its diet. The species was blamed for the death of two men in New Guinea back in 2011, when a Pacu bit their testicles and they suffered severe blood loss.

It is likely that DePersia's discovery wound up in the lake after being dumped there by a collector when the fish became too large for its tank, according to the New Jersey Star-Ledger.

DePersia plans to keep his find and use it scare off unwanted visitors at his home.

"I'll probably stuff it and put it on my porch there when I get it done," he said.

However, officials at the Shedd Aquarium in Chicago told CBS that the fish isn't usually a threat to humans.

This is not the first Pacu found in waters outside of its tropical home recently. A 10-inch Pacu was found in a lake in Passaic County, N.J. two months ago, while sightings in Paris and Sweden have also been noted in recent months. A Pacu was also reportedly found in Illinois last summer in Lake Lou Yeager, The Huffington Post reported.