Happy, a 55-year-old Asian elephant who resided at the Bronx Zoo since 1977, was euthanized due to declining health conditions, including issues with her kidney or liver function. Zoo officials made the decision after assessing her quality of life during hospice care. Happy gained notoriety not only for her long life but also for her remarkable intelligence, which led to a significant legal case regarding animal rights. In 2018, the Nonhuman Rights Project argued that she should be granted the same legal protections as humans under the principle of habeas corpus, claiming her confinement at the zoo was illegal. However, New York's highest court ultimately rejected this argument in a 5-to-2 ruling. Happy was notable for being the first elephant to pass a mirror self-recognition test, demonstrating a level of self-awareness previously only observed in humans, apes, and dolphins. Christopher Berry, the executive director of the Nonhuman Rights Project, stated that Happy's legacy would continue to inspire efforts for animal rights.