What do you call a giant, tropical fish with big ass human teeth that enjoys using them for chomping down on human testicles, and has mysteriously starting showing up on continents where it shouldn't even be? That's a little something we like to call nightmare shit.

British newspaper The Mirror says that there are worries the piranha cousins from the Amazon jungle known as the pacu could begin showing up in English waters, since it has already appeared in lakes and rivers in other parts of Europe. The Independent reported that the nightmarish fish have been found in the Øresund channel between Denmark and Sweden, as well as in Paris in the River Seine.

You definitely wouldn't want to go skinny dipping around these bad boys that grow as big as three feet long and are apparently nicknamed "The Nut Cracker" or "The Ball Cutter."

Here's what a fish expert told the newspaper:

"The pacu is not normally dangerous to people but it has quite a serious bite. There have been incidents in other countries, such as Papua New Guinea where some men have had their testicles bitten off.

"They bite because they’re hungry , and testicles sit nicely in their mouth."

The fish normally use their powerful jaws for breaking open nuts, the kind that come from trees, when they fall into the water.

And before you laugh, remember that Americans aren't necessarily safe either. These testicle munchers have over the past few years been caught in Florida, California, New Jersey and a dozen other U.S. states—keep you trunks on this summer.

The craziest part might be that the pacu is only the second most nightmarish, genital-threatening animal species to make its way from South America to Europe recently.