The term 'TADPOLE's Parent' is a four-letter word that can be solved by the crossword answer 'FROG'. Frogs are amphibians that belong to the order Anura, which includes over 4, 000 species. They are characterized by their long hind legs, webbed feet, and protruding eyes. Tadpoles are the larval stage of frogs, and they develop into adult frogs after undergoing metamorphosis. Therefore, the parent of a TADPOLE is a FROG.