A young Kemp’s ridley sea turtle, one of the world’s most endangered turtle species, was found off the coast of Portugal and brought to a rehabilitation center. Despite intensive care, the turtle died after 11 days due to a severe fungal lung infection caused by Beauveria bassiana, a fungus that normally infects insects. This case highlights how endangered animals in poor health are vulnerable to opportunistic infections and emphasizes the importance of including fungal disease screening in wildlife rehabilitation programs.