More than any other mutant on Earth, biologists are baffled as to the origin of these great apes. There are fragments of documents from the far-flung past that mention other human-like primates, but none were ever known to grow so large or inhabit the Confederacy.
Gruntags are not only dumb and vicious, they have been witnessed committing unspeakable acts of cruelty to any animal they can get their paws on, including other gruntags. It seems that their only proclivity to intellect is when seeking a new kind of murder.
Outside the darkest, crumbling ruins of hotels and office buildings where they make their caves, stand pikes with corpses turned inside out, creatures whose every bone has been meticulously broken, or the gruesome remains of thrashing animals and humans alike who have been kept alive…but just barely.