i never heared if these ultrasonic foggers are safe for animals or not. They might be, im just unsure. I know an ultrasonic cleaning bath can hurt you.

i would make sure the snake cannot get too close to the fogger. i mean, it sends out shockwaves powerful enough to cause cavitation in the water and to rip apart the water into tiny droplets. it wont have an effect at a distance, so it should be safe if you add the protection that you would also use for a lightbult that can get hot. but maybe its safe, it depends on how much weaker the shockwaves are, compared to an ultrasonic cleaning bath.

but then, if you can put your finger into the water right in the area where the fog is coming from, and it doesnt turn red and swollen afterwards, i guess its safe.