Deadly Nightshade (Atropa belladonna)
Because yes. In Australia even the plants can kill you. Looking very similar to blueberry varieties that commonly grow around the country, this little berry is deceptively sweet when bitten into but just two berries can kill a child. It only takes 10 or 20 to kill an adult. Don’t even think about the leaves. Eating one of these is enough to do the job.