Hastings' Dictionary of the Bible (1898)
FROG, a well-known amphibious reptile which lives on insects, worms, etc. Ex 8:2. But one species is found in the waters of Egypt (Rana caculenia). In Rev 16:13 this creature is the symbol of uncleanness. Ex 8:2 records the miraculous multiplication of frogs among the Egyptians in such numbers as to fill their beds, ovens, and kneading-troughs; and when they died, as they did in immense masses, they filled the land with an offensive and
pestilential effluvium.