וַיַּֽעֲשׂוּ־כֵ֥ן הַֽחֲרְטֻמִּ֖ים בְּלָטֵיהֶ֑ם וַיַּעֲל֥וּ אֶת־הַֽצְפַרְדְּעִ֖ים עַל־אֶ֥רֶץ מִצְרָֽיִם׃
And the magicians did in like manner with their secret arts, and brought up frogs upon the land of Egypt.
Read kabbalistic (mystical) interpretation of Exodus 8:3: and classical mystical sources.