There's not a whole lot of dangerous wildlife about at that time of year. Lizards are harmless, tarantulas are extremely cool and basically harmless unless you go out of your way to piss 'em off. You might see black widows in wood piles and utility boxes, so leave 'em alone or kill them, your choice.
Scorpions? Haven't seen any, but don't be rolling around in the bushes. Don't leave your shoes outside or at least shake them out before putting them on. A scorpion sting is more or less like a bee or wasp sting in severity most of the time. They glow under black light, so if you have a black light you might find one at night.
Rattlesnakes get pretty dormant in the cold, but I wouldn't be sticking hands or feet into places you can't see. Leave them alone, they eat plenty of vermin. Leave other snakes alone too, even the harmless ones that pretend to look like rattlers, e.g. gopher, garter, king snakes. Don't let your dogs harass snakes or lizards either. If a dumb dog gets bit by a rattler, it's your fault, not the snake's fault or the dog's fault. And saving your dog's life will cost you.
Mice and pack rats love cars and trucks and RVs, so pop the hood open when you park and consider stringing some solar powered LED xmas lights under the vehicle and inside the engine to deter them, otherwise they'll nest and chew up your delicious wiring.
You will hear (and possibly see) coyotes, and they love to eat pets. Keep them inside or on leash at ALL times. They are smart as the devil and will cooperate to lure dogs into chasing after one so the rest of the pack can take it down and kill it.
The big tall cactuses with the branching arms (Saguaros) are harmless as long as you aren't hugging them or in their path if they fall over. They weigh several tons and if there's been a lot of rain they get even heavier and may start to rot at the bottom. Prickly pears and chollas (related to each other) are nasty af though. These in particular have fine, almost invisible spines that stick to your skin and clothes and are REALLY irritating, like way worse than fiberglass in your skin. Chollas are also known as "jumping cactus" because the spines you CAN see have barbs on the ends and will attach themselves to anything passing close enough to nudge them. Most people don't tangle with these after the first incident.
Bring a bandana / buff / dust mask. Idiot ATV and dirt bike drivers can kick up a lot of dust. Dust in Arizona and southern California can carry Valley Fever, a fungal infection (coccidioidomycosis) that can make you a little bit sick (or a lot) and is not well known to doctors and hospitals outside areas where it is endemic. It's been a wet year in the west, which makes for way more spores than usual, and you can catch it from inhaling blowing dust. Dogs can catch it too, cats as well but less often, which is another reason to keep your pets on leash and under control.
Before you park, GOAL (Get Out And Look). Don't camp in washes (runoff areas for flash floods), creek beds, dry lakes, etc. It's been a wet year, the ground is still saturated in many places, and a sudden intense rainstorm leaves no place for the water to soak into the ground, so you get flash floods. This isn't just a little creek of rainwater, it's a deep rolling river of mud, boulders, rocks, tree limbs, debris, and whatever else is in its path, going faster than you can run or sometimes drive. Don't drive into an area that is flooding, as the road may be gone underneath and you can be swept away. I'm not exaggerating.
Probably none of this will happen, so just keep your eyes open, use a little common sense, and have a great time.
I don't take my dog anywhere near water around here because we have lots of them, little ones, big ones and prehistoric monsters. I was fishing once in my little 12 foot boat and drifted past a beast longer than my boat and it jumped right off the bank at me. i was done fishing for the day.
