The term 'Tropical Nocturnal Mammal' can be summarized by the crossword solution 'TAPIR', which is a five-letter word. Tapirs are large, herbivorous mammals that live in tropical regions of South and Central America, Southeast Asia, and parts of China. They are nocturnal animals, meaning they are active at night and sleep during the day. Tapirs have a long prehensile snout and are related to horses and rhinoceroses.