Was working on a rural conventional unit, setting on a concrete pad.Wiring in control panel was spaghetti, sorting out the wiring , when out of the corner of my eye I noticed some of the wires were moving w/o me touching them. Baby copperhead. People that worked there told me they were always found in pairs. Just a little leery after that.
That looks like an Eastern Diamondback rattler. Would be more realistic if the rattles were flopped over--they don't get an erection when aroused, they flutter off to one sde. Also, they keep their mouths closed until during the strike. Otherwise, they cannot sense you as well. The tongue must be sampling the air and wiping it against a sensory organ in the roof of the mouth.
Now, if you added a motion sensor to sound effects and a flickering tail, well.....
I pulled out a line set on a change out one day and found a pigmy rattler about 2 feet in it came out with a bad attitude and scared me half to death i found a new use for my pvc cutters that day i wish the guy who did the original install would have foamed that chase also i seen a guy get attacked by a woodpecker putting a cap on a dryer vent on a rough in it was hilarious after i knew he was ok after falling off an extension ladder haha it got him right on the forehead