You'd be surprised at how deadly those could actually be. They have the same toxin in them as apple seeds, but cooking them deactivates this toxin, making cooked kidney beans safe to eat. However, if you cook it at a temperature lower than 100 degrees or so, it makes the toxin stronger, to where a single bean can have you blasting out both ends in a painful, gross, and dehydrating death. If you're wondering where I learned this, here's the link: https://m.youtube.com/watch?v=yj8bgNaW2lk
It would actually be the perfect way to murder someone, because not only is it perfectly legal and easy to buy raw kidney beans, but once the person's dead and they start asking questions, you could just play it off like you didn't know that that would happen.