(א) וַיֹּ֣אמֶר יקוק אֶל־מֹשֶׁה֒ אֱמֹ֣ר אֶֽל־אַהֲרֹ֗ן נְטֵ֤ה אֶת־יָדְךָ֙ בְּמַטֶּ֔ךָ עַ֨ל־הַנְּהָרֹ֔ת עַל־הַיְאֹרִ֖ים וְעַל־הָאֲגַמִּ֑ים וְהַ֥עַל אֶת־הַֽצְפַרְדְּעִ֖ים עַל־אֶ֥רֶץ מִצְרָֽיִם׃ (ב) וַיֵּ֤ט אַהֲרֹן֙ אֶת־יָד֔וֹ עַ֖ל מֵימֵ֣י מִצְרָ֑יִם וַתַּ֙עַל֙ הַצְּפַרְדֵּ֔עַ וַתְּכַ֖ס אֶת־אֶ֥רֶץ מִצְרָֽיִם׃ (ג) וַיַּֽעֲשׂוּ־כֵ֥ן הַֽחַרְטֻמִּ֖ים בְּלָטֵיהֶ֑ם וַיַּעֲל֥וּ אֶת־הַֽצְפַרְדְּעִ֖ים עַל־אֶ֥רֶץ מִצְרָֽיִם׃ (ד) וַיִּקְרָ֨א פַרְעֹ֜ה לְמֹשֶׁ֣ה וּֽלְאַהֲרֹ֗ן וַיֹּ֙אמֶר֙ הַעְתִּ֣ירוּ אֶל־יקוק וְיָסֵר֙ הַֽצְפַרְדְּעִ֔ים מִמֶּ֖נִּי וּמֵֽעַמִּ֑י וַאֲשַׁלְּחָה֙ אֶת־הָעָ֔ם וְיִזְבְּח֖וּ לַיקוק׃ (ה) וַיֹּ֨אמֶר מֹשֶׁ֣ה לְפַרְעֹה֮ הִתְפָּאֵ֣ר עָלַי֒ לְמָתַ֣י ׀ אַעְתִּ֣יר לְךָ֗ וְלַעֲבָדֶ֙יךָ֙ וּֽלְעַמְּךָ֔ לְהַכְרִית֙ הַֽצְפַרְדְּעִ֔ים מִמְּךָ֖ וּמִבָּתֶּ֑יךָ רַ֥ק בַּיְאֹ֖ר תִּשָּׁאַֽרְנָה׃ (ו) וַיֹּ֖אמֶר לְמָחָ֑ר וַיֹּ֙אמֶר֙ כִּדְבָ֣רְךָ֔ לְמַ֣עַן תֵּדַ֔ע כִּי־אֵ֖ין כַּיקוק אֱלֹקֵֽינוּ׃ (ז) וְסָר֣וּ הַֽצְפַרְדְּעִ֗ים מִמְּךָ֙ וּמִבָּ֣תֶּ֔יךָ וּמֵעֲבָדֶ֖יךָ וּמֵעַמֶּ֑ךָ רַ֥ק בַּיְאֹ֖ר תִּשָּׁאַֽרְנָה׃ (ח) וַיֵּצֵ֥א מֹשֶׁ֛ה וְאַהֲרֹ֖ן מֵעִ֣ם פַּרְעֹ֑ה וַיִּצְעַ֤ק מֹשֶׁה֙ אֶל־יקוק עַל־דְּבַ֥ר הַֽצְפַרְדְּעִ֖ים אֲשֶׁר־שָׂ֥ם לְפַרְעֹֽה׃ (ט) וַיַּ֥עַשׂ יקוק כִּדְבַ֣ר מֹשֶׁ֑ה וַיָּמֻ֙תוּ֙ הַֽצְפַרְדְּעִ֔ים מִן־הַבָּתִּ֥ים מִן־הַחֲצֵרֹ֖ת וּמִן־הַשָּׂדֹֽת׃
(1) And יקוק said to Moses, “Say to Aaron: Hold out your arm with the rod over the rivers, the canals, and the ponds, and bring up the frogs on the land of Egypt.” (2) Aaron held out his arm over the waters of Egypt, and the frogs came up and covered the land of Egypt. (3) But the magician-priests did the same with their spells, and brought frogs upon the land of Egypt. (4) Then Pharaoh summoned Moses and Aaron and said, “Plead with יקוק to remove the frogs from me and my people, and I will let the people go to sacrifice to יקוק.” (5) And Moses said to Pharaoh, “You may have this triumph over me: for what time shall I plead in behalf of you and your courtiers and your people, that the frogs be cut off from you and your houses, to remain only in the Nile?” (6) “For tomorrow,” he replied. And [Moses] said, “As you say—that you may know that there is none like our God יקוק; (7) the frogs shall retreat from you and your courtiers and your people; they shall remain only in the Nile.” (8) Then Moses and Aaron left Pharaoh’s presence, and Moses cried out to יקוק in the matter of the frogs which had been inflicted upon Pharaoh. (9) And יקוק did as Moses asked; the frogs died out in the houses, the courtyards, and the fields.
The word צְּפַרְדֵּעַ is another word in the Torah that I find very strange (see alsַo שַׁעַטְנֵז and צִיצִת). It is translated as "frog", but why this particular word (i.e., its spelling)?
One approach to an answer is connected to the seemingly compound nature of צִּפֹּר + דע :צְּפַרְדֵּעַ. If דע is דַּע, then this would be "bird" and "know". The ibis, for instance, was a sacred bird in Egypt and perhaps was known to eat frogs (see here). If דע is דֵּעַ, then this would be "bird" and "knowledge". Perhaps it was known that frogs could recognize the threat from birds and were known to evade them. These are not mutually exclusive. Although odd, maybe צְּפַרְדֵּעַ for "frog" has to do with the fact that some birds eat frogs.
Another approach is connected to the word הַצְּפַרְדֵּעַ in Ex. 8:2. An anagram for it is: צד + פַּרְעֹה. If צד is צָּד, then it would be "hunt" and "Pharaoh". If צד is צַּד, then it would be "side" and "Pharaoh".
Support for this second approach to an answer can be found in Ex. 8:4 and 8:8:
(ד) וַיִּקְרָ֨א פַרְעֹ֜ה לְמֹשֶׁ֣ה וּֽלְאַהֲרֹ֗ן וַיֹּ֙אמֶר֙ הַעְתִּ֣ירוּ אֶל־יקוק וְיָסֵר֙ הַֽצְפַרְדְּעִ֔ים מִמֶּ֖נִּי וּמֵֽעַמִּ֑י וַאֲשַׁלְּחָה֙ אֶת־הָעָ֔ם וְיִזְבְּח֖וּ לַיקוק׃
(ח) וַיֵּצֵ֥א מֹשֶׁ֛ה וְאַהֲרֹ֖ן מֵעִ֣ם פַּרְעֹ֑ה וַיִּצְעַ֤ק מֹשֶׁה֙ אֶל־יקוק עַל־דְּבַ֥ר הַֽצְפַרְדְּעִ֖ים אֲשֶׁר־שָׂ֥ם לְפַרְעֹֽה׃
(8) Then Moses and Aaron left Pharaoh’s presence, and Moses cried out to יקוק in the matter of the frogs which had been inflicted upon Pharaoh.
Pharaoh complains about the frogs, feeling personally threatened by them. The frogs have been inflicted upon him.
The frogs (הַצְפַרְדְּעִים) at Pharaoh's side are hunting him.