This sounds like it could be the plot for the next Godzilla movie but the NY Times reports the area of Japan where a Tsunami and subsequent reactor meltdown occurred in 2011 has been overrun with wild, radioactive boars:
Hundreds of toxic wild boars have been roaming across northern Japan, where the meltdown of the Fukushima nuclear plant six years ago forced thousands of residents to desert their homes, pets and livestock. Some animals, like cattle, were left to rot in their pens.
As Japan prepares to lift some evacuation orders on four towns within the more than 12-mile exclusion zone around the Fukushima plant later this month, officials are struggling to clear out the contaminated boars.
Wild boar meat is a delicacy in northern Japan, but animals slaughtered since the disaster are too contaminated to eat. According to tests conducted by the Japanese government, some of the boars have shown levels of radioactive element cesium-137 that are 300 times higher than safety standards.
There has been a 20-kilometer exclusion zone around the Fukushima nuclear plant since the disaster. Some residents are now being allowed to return to their homes in the more distant areas, but the wild boars, which can get fairly large, now consider these abandoned towns home and are not afraid of people.
Since 2014, the number of boars killed has grown from 3,000 to 13,000. As you can see in this clip below, hunters have been hired to shoot the animals by the hundreds but many will remain when people begin returning to the region. One hunter says, “They found a place that’s comfortable, there’s plenty of food and no one will come after them.” He adds, “This is their new home now and this is where they have children.”
In addition to the radioactive boars, the area also has packs of wild dogs and large colonies of rats which took over supermarkets when people abandoned the area in 2011.