The common names of species are an important communication tool used by conservation researchers when engaging with stakeholders and the public. Using the common names of nearly 27,000 animals from the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, we performed a sentiment analysis to investigate words in common names that drive sentiment and are associated with human emotions. We found that words driving sentiment varied across taxonomic class and threat status, and some highly frequent words are associated with negative emotions (e.g., fear, disgust). We show that strategic name changes have potential to improve public engagement and support for threatened species and therefore to provide effective, low-cost benefits to conservation outcomes.