Cyanide was a roman favorite and may have been useful in artillery warfare.
One thing I'm not keen to try is hunting an animal with poison. For starters, in the amount of time it might take an animal to die or stop running, it would be relatively easy to lose track of where it bolted off to. The other thing is that I might be going to all of that trouble just to end up with poisoned meat.
My old man used to refer to someone being shot to death as death by lead "poisoning".
My friend who is a geologist once called an enormous boulder, that's above and a bit too close to a road we drive on, a poisonous rock. When I asked why the rock was poisonous, he said that just one drop would kill me.