Since their introduction in 1935, cane toads have spread out across the top of Australia, leaving a wave of death in their wake: animals poisoned by the unfamiliar toxins they carry. While management efforts have focused on lethal interventions, one group of scientists has been attempting to teach native animals-including monitor lizards, quolls, crocodiles, and others-not to eat toads through a 'conditioned taste aversion' that is produced with the use of nauseating toxins. This Element explores the history, ethics, and emergent possibilities of this ongoing multispecies pedagogical experiment. It asks how the toxic substances that are deployed by both toads and scientists open up new opportunities for learning, for becoming differently together, for reshaping ecosystems and shared lives, while also carrying with them significant, often mortal, dangers. Ultimately, the text explores a complex space of biodiversity conservation centred on the cultivation of a thoroughly imperfect, but hopeful, 'craft of poisoning'.