Cnidocytes are specialized cells found in cnidarians, such as jellyfish, corals, and sea anemones. These cells contain organelles called nematocysts, which can eject a stinging thread to capture prey or defend against predators. Upon contact, cnidocytes trigger a rapid response, injecting toxins that can immobilize or deter threats. This unique adaptation plays a crucial role in the survival and feeding strategies of cnidarians.