In the 'verse I created, the world was ravaged by an international Resource War, including EMP strikes on the US, then meteors striking around the world, wiping out most life, and introducing a mutanagenic dust.
If you're interested in a more complete timeline, let me know.
I'm looking for:
Raiders, local settlements, ex-military, etc.
So far I have:
5th Horseman - Doomsday cult that is trying to finish what the meteors started. American South
Mazons - Matriarchal society
Devil Riders - Mobile gang in midwest. Very Mad Max
Whiteshirts - Cleanest group around. Vault-ish, but not psycho. They have supplies and want to educate the wastes.
Scrappers - Mercs/Scavengers who are not afraid to fight, and mostly employ clubs, knives and makeshift knuckle dusters/boxing gloves, and weapons you find in the trenches of WWI. Big on the West Coast
Dustmen - Scavengers that brave the radioactive cloud looking for raw/rare materials and non scavenged parts, should be shrouded in long makeshift robes(Covered to the last like people travelling in the middle east), goggles, masks, and cloaks that they always wear. Carry walking spears/sticks and rifles, maybe sometimes use bikes/cars but prefer to save resources. Seen up and down the east coast.
New Liberty - Protectorate military group based out of Ft. Bragg in North Carolina.
Ash Runners - NY based marauder army. Eventually defeated and pushed out to sea on flaming ships.
Clarifiers - Christian faithful that go from place to place setting up water-purification systems. Nationwide
The Redeemed - Cannibals trying to change their ways. Appalachia. Pushed in the new direction by the Clarifiers.
Gorgons - Reckless vigilante group. Hunts raiders, but doesn't care about collateral damage.
Dead Men – Raiders based out of Leavenworth started as freed prisoners.
Faceless – Cultists in the Great Lakes area, wear featureless masks
Eclipse Stalkers – Mercs based out of Camp Lejune
Red Moon - Marauders that started in the NC coast area and are working their way west. Currently fighting New Liberty
White Ashes - a broken-off faction of the Ash Runners of southern NY fame. The group broke away before the Siege of the Big Apple (or some other cool name for New York City as suggested by you!), making their way south hoping to sack the ruins of DC and Baltimore. They tend to favor flame weapons.
New Sun Legion –
Rose Knights –
Bone Collectors -
Forsaken – Assassin group, nationwide.
New Start Alliance – Mixed SRC and NAWA group that started in the war-torn Pacific Northwest.
Animals/humans changed by the meteor dust.
So far I have:
Ogres – Large, very cunning and dangerous. Typically deformed with one arm much larger than the other.
Dusters – Zombies, mindless zombies
Cannies - Feral cannibals
Hellbender – Giant salamander
Stone Toads – Big frog, eats anything, poisonous to step on, looks like a rock.
Blister Bunny – Rabbit covered in colored blisters that change with volatility. Explode when over-scared, but the blister goo is useful medicinally
Hogzilla – Giant pig, big tusks
Drakken – Giant snake
Tortoise Rex – Big, carnivorous turtle
Near Deer – Six legged mutants
Dire Deer – Carnivorous deer
Crok – Giant six legged crocodiles
Sprat – Spider-rat hybrid
Porky – Ankylosaurus-like porcupine
Stymphies - Big birds
Rocs - Birds of prey the size of elephants. Known for picking up vehicles and dropping them to crush the humans inside/break them open. Hunt from the Rocky Mountains
Hellhounds - Dogs and wolves mutated into larger and more ferocious forms. Spread from the east.
Cretins - Opposite of ogres, undeformed deformed mutants with stunted growth, equal to dwarfism or smaller, cowardly by nature but effective in numbers, good at sneaking and stealing due to their small size. Live in sewers and abandoned buildings
Rotbeak(Bone-vulture)(Corpse Condor) - A giant vulture/condor bird mutant that preys on the dying and weak in the wasteland, the sands of the cloud have made the already loose flesh raw, to the point where parts of the bone structure are visible, look a bit like skeksis from dark crystal. Typically seen in areas with large raider populations,
Wendigo - Powerful - high tier- mutant cannibal stalker, eviscerates and feasts on anything it can find, always on the hunt for prey. Ogre variant. Seen across northern America, in heavily forested areas
Ranas - Small birds that swarm prey like piranhas
Vikkoon (Vye-coon) - Massive pack hunting raccoons
Breathers - Mutant lungfish. Live in rivers, known for their ragged breathing.
Catoblepas - Mutant moose. Big heavy head,
Night Shockers - Electric zappy cricket
Rens - Mutant fox
Wampus - Mutated cougars in Appalachia with the ability to stand on their hind limbs, long prehensile tails, much bulkier bodies, and sickle-like claws.
Rahab - Mutated whale with a much longer, more elongated body, clawed fingers on the flippers, and sharp teeth
Umbo - Huge mutated elephants descended from escaped circus elephants in Florida, based on the Mumakil from LOTR, with clawed feet, extra tusks, the works.
Bloodbeaks - Mutant mosquito
Samnus - Mutant hornet. Named by Asian SRC members caught on US mainland
Gammarachnid - Mutant spider
Fireflies - Kamikaze pyro bugs. Can be used for fuel if killed before flaming out.