Pigs. Pigs take one generation to revert to feral state and are naturally pack hunting, intelligent, omnivores. Right now Texas and Florida is dealing with cases of hogs pulling apart horses to eat. There are cases where the hogs followed hunters home and trashed the place in retaliation.

It’s a testament to our hubris that we’ve kept pigs and dogs for so long. Dogs won’t recover, but pigs only need a year to come back for blood.