This chapter from Outdoor Emergency Care: A Patroller’s Guide to Medical Care provides essential information for outdoor emergency care technicians regarding injuries and illnesses resulting from encounters with plants and animals. It defines key terms like poisons, toxins, and venom, and describes potential harm from various biological sources, including toxic plants, poisonous mushrooms, spiders, snakes, insects, and marine life. The chapter outlines patient assessment techniques specific to these situations, emphasizing scene safety and recognizing signs of envenomation or poisoning. Furthermore, it details the proper management of such emergencies, covering topics like stinger removal, tick removal, snake bite care, and treatment for animal bites, always prioritizing life-threatening conditions and transport when necessary, as illustrated in the included case study.