Strange things, phobias.
Over the years I've known people with all sorts of weird ones but two which stick in my mind are... cotton wool, which was the phobia of a boyfriend's sister and the other one was a friend whose phobia was forks which become entwined with each other.
My own phobia is snakes and it is very real.
Re - Canary's mutilation phobia. That's an interesting one. Is that related to the missing body part - or the remaining body which is now minus the part?
I see a body with a missing part as simply incomplete but not necessarily distressing to an observer... but I can understand why a dismembered body part causes distress when not attached to its body. That said, amputated fingers and toes are much less "scary" than arms, legs etc.