Need to show how the Phlebotinum Du Jour affects living things, but the character isn't evil enough to test it on an animal? Well, plants are fair game. Therefore, plants tend to get mistreated a lot in fiction. Do you suspect that your friend is infected with The Virus or some sort of radioactivity? Do you want to make sure it's still safe to go near him? Have him go near a potted Ficus. If your friend is dangerous, the tree will instantly shrivel and die, all its leaves falling off at once. Examples of That Poor Plant include: