Species common names underpin communication between researchers, stakeholders and the public. Changing unappealing (e.g., rough-skinned horned toad), misleading (e.g., lesser bird of paradise) or even immemorable (e.g., little grassbird) species names could be an effective, and inexpensive, way to improve engagement with and support for threatened species. We use two sentiment lexicons to analyze the common names of 26,794 IUCN Red List animal species to understand which words drive sentiment in species names. Words driving common name sentiment varied across taxonomic class and threat status; highly frequent words associated with human emotions included anger, fear, disgust, and joy. We identified keywords for future targeted research on strategic name changes (e.g., greater, golden, least, lesser, false). This article provides essential grounding for future species common name research and improving public engagement with threatened species.