if you use a slingshot on a raccoon, with a rock around the size of a 10cm, there is a really good chance that you can actually do damage.

in areas where there are a lot of people and or things that could get damaged, I often used dried beans, like Kidney beans.

I used to live in an area where the houses were all old victorians, with a lot of french windows.
raccoons would congregate on roof tops, in a weird social/mating display which grossed me out to no end, not to mention crazy noisy.
So i'd spot them with my bike light and peg them off with kidney beans.
that alone is a pretty hard hit. it would definitely make a dog yelp, piss of your buddy if you hit him, make a horse/deer/cow, etc.. they'd definitely take off running.
its the sharp and sudden sting.

if you use things like rocks, you'll probably break ribs on small animals.
a walnut sized rock for a bear... is decent. its just the simple act of being near a human, and having something suddenly whiz past, shatter, etc...
I've hit a few bears, less than a dozen for sure. I've never had to shoot at one as they were approaching, luckily I've been afforded nice big side profile shots.
maybe its really mean... but somehow there is this kind of primal gratification.

a wrist rocket is really CRAZY!