I love realistic looking pets, so I'm excited for this event!
Here are some of my predictions of what pets/items will be inspired by.
MAMMALS
Armadillo
Prairie dog
Ground squirrel
Kangaroo rat
Jackrabbit
Mountain lion/cougar/puma
Bobcat
Mexican wolf
Coyote
Kit fox
Gray fox
Ringtail
Raccoon
American badger
Weasel
Black-footed ferret
Western spotted skunk
Striped skunk
Pronghorn antelope
Bison
Bighorn sheep
Collared peccary
Lots of horses, especially paint/pinto, appaloosa, roan, dun, buckskin
Mules
Donkeys
Cattle, especially Texas longhorns
BIRDS
Turkey vulture
California condor
Bald eagle
Golden eagle
Northern harrier
Red-tailed hawk
Swainson's hawk
Harris's hawk
Cooper's hawk
Crested caracara
American kestrel
Aplomado falcon
Prairie falcon
Peregrine falcon
Elf owl
Burrowing owl
Greater roadrunner
Scaled quail
Gambel's quail
California quail
Gila woodpecker
Red-shafted northern flicker
Costa's hummingbird
Barn swallow
Cliff swallow
Thrasher
Northern mockingbird
Loggerhead skrike
Phainopepla
Pyrrhuloxia/desert cardinal
Black-billed magpie
Cactus wren
Western meadowlark
Brown-headed cowbird
Mourning dove
Raven
REPTILES
Gopher tortoise
Collared lizard
Leopard lizard
Chuckwalla
Horned lizard
Spiny/fence lizard
Banded gecko
Western alligator lizard
Gila monster
Whiptail lizard
Rubber boa
Rosy boa
Trans-Pecos ratsnake
Gray-banded kingsnake
California kingsnake
Milksnake
Gopher snake
Gartersnake
Hognose snake
Western diamondback rattlesnake
Sidewinder
Sonoran coral snake
ARTHROPODS
Aphonopelma spp.
Wolf spider
Black widow
Hadrurus spp.
Dune scorpion
(I would LOVE a scorpion under blacklight!! That would be such a cool design)
Giant vinegaroon
Solifuge
Blue death-feigning beetle
Darkling beetle
Rainbow scarab
PLANTS
Barrel cactus
Saguaro cactus
Cholla cactus
Beavertail cactus
Organ pipe cactus
Prickly pear cactus
Ocotillo
Joshua tree
Yucca
Agave
Mesquite
Palo verde
Oak
Jojoba
Desert sage
Wildflowers of all kinds
OTHER
Tumbleweed
Minecart
Train
Train coaches
Stagecoach
Horse-drawn carriage
Wagon
Wagon wheel
Railroad tracks
Railroad spike (I feel like this could be the next event token)
Golden spike
Pickaxe
Gold
Coal
Ore
Stick of dynamite
Box of dynamite
Barrel
"Liquor" bottles
"Beer" mug
Skulls (especially cow skulls)
Horseshoe
Lasso
Cowboy/cowgirl outfits
Sheriff outfit
Outlaw outfit
Zorro-inspired outfit?
Late 1800s dresses
Late 1800s suits
Pocket watch
Moustaches
Guitar
Old windmill
Water tower
Clock tower
Bandanas, neckerchiefs
Tent
Playing cards
Candles
Oil lamp
Oil lantern
Sack of money
Stocks (those wooden things criminals were locked in)
Wooden piano
Western tack
Canyon, mesa, desert, plains scenery
Piece of straw item that sticks out of the pet's mouth
Old-timey guns (rifle, revolver) are quintessentially Wild West, but I doubt they'll make an appearance considering the holster items on CS (2013 Halloween) have bananas inside them.
Going to look back on this post at the end of the event and see what I was right about