Destructive “super pigs” from Canada are beginning to invade the U.S., threatening to add to the billions of dollars in damage already inflicted annually upon the nation by feral swine.

Dr. Ryan Brook, lead on the University of Saskatchewan’s Canadian Wild Pig Research Project, told Field and Stream earlier this year, “The U.S. has a 400-plus year history with invasive wild pigs, but we didn’t have any here until the early 1980s.”

“There was a big push to diversify agriculture with species like wild [boars] and ostriches. Wild boars were brought in from Europe to be raised on farms across Canada,” said Brook.

The swinish imports from Eurasia, kept both on meat farms and in hunting preserves, were crossbred with domestic pigs, resulting in “super pigs.” These monstrosities were not only larger, but hardier and capable of surviving in cold climates.