In Exodus 8:2 and Psalm 105:30, frogs signify reasonings from falsities, for they crawl from the river, and the waters of Egypt signify falsities of doctrine (Arcana Coelestia 7351-7352)

In Exodus 8:8, this signifies that they should not be driven to reason from mere falsities -- which is why Pharaoh deprecated the plague of frogs, but not that of the blood. (Arcana Coelestia 7392[2])

In Revelation 16:13, frogs signifies reasonings from lusts of falsifying truths. They signify also unclean spirits of the lowest sort. (Apocalypse Revealed 702; Arcana Coelestia 1956)