Toxic organisms are living beings that produce harmful substances, which can be detrimental to other organisms, including humans. These toxins can be found in various forms, such as bacteria, fungi, plants, and animals. For example, some species of mushrooms contain potent toxins that can cause severe illness or death if ingested. Many toxic organisms have evolved these defenses to deter predators or compete for resources. Pufferfish, for instance, contain a toxin called tetrodotoxin, which can be lethal. Understanding these organisms is crucial for public health and safety, as well as for ecological balance in their environments.