Shadow totems? Hmm, hard for me, since, imho, people who hate snakes and spiders simply "have no soul"... lol!
But your mentioning nightmares gave it to me... the rat! (Not too crazy about mice either, the thought of small, swarming, seething rodent hoards under the floorboards just gives me creeps!)
Strange, because in other ways, rats and mice (at a distance) seem quite cute, warm, furry, warm-blooded, and you have to love a mouse's small, glistening, bright eyes... I could respect one guy's affection for his pet rat when he held it, although I could not; with mice, the thought that, if you see one in your house, means that ten others lurk beneath the floorboards, drove me (because I still do not like the unnecessary cruelty of poison, even in their case, and the thought of having to dispose of a trap with a dead rodent body in it just gave me the heebie-jeebies) to borrow the mouse's natural predator, a CAT!!! And at that point, the cat and I really bonded, as the cat supplied me with Tom-and-Jerry cartoons of ruthless efficiency in disposing of mice... hehe ;-))
I could tolerate mice in a small mouse house for my son, then at kindergarten age, but when they gnawed through the chipboard and escaped, I felt happy to pass it on to the local kindergarten as a 'donation', then to become their problem...
Rats became my nightmare on reading Camus' The Plague in Year 12; I also picked up my Norwegian mother-in-law's worst nightmare, in Norway, of rats tumbling out of a hole in the wall... Interestingly, a common species of rat, along with 'Rattus rattus', gets called 'rattus norvegicus'? Perhaps an encapsulation and anticipation of the traumatic, as opposed to idyllic, aspects of my whole Norwegian experience?
In other ways, I respect their intelligence, so like our own, and the fact that they alone, along with cockroaches (*shudder!*) stand to inherit the earth in the event of catastrophe...
Strangely enough, I have rat, in a perfect Chinese trine, with monkey and dragon in my Chinese horoscope. Something about "the perpetual student" in me, greedy, but more so for knowledge rather than food... I would love to have a rat suck up to me, and fawn on me, as monkeys famously suck up to, and fawn on, dragons... ;-))
I still don't like them much, but I respect them more and more as a shadow totem every day ;-))
OK, enough about mine; your shadow totems, anybody? ;-))