Devarim 4:18

18 The likeness of anything that creepeth on the adamah, the likeness of any dag (fish) that is in the waters below;

Devarim 4:18 Meaning and Commentary

Deuteronomy 4:18

The likeness of anything that creepeth on the ground
As serpents by many; and indeed that creature is introduced into almost all the idolatries of the Heathens, which seems to take its rise from the serpent Satan made use of to deceive our first parents:

the likeness of any fish that is in the waters beneath the earth;
as the crocodile and hippopotamus, or river horse, by the Egyptians; and Dagon and Derceto, supposed to be figures in the form of a fish, among the Phoenicians.

Devarim 4:18 In-Context

16 Lest ye corrupt yourselves, and make you a pesel, the temunah of any semel, the likeness of zachar or nekevah,

17 The likeness of any behemah that is on ha’aretz, the likeness of any winged fowl that flieth in the air,

18 The likeness of anything that creepeth on the adamah, the likeness of any dag (fish) that is in the waters below;

19 And lest thou lift up thine eyes unto Shomayim, and when thou seest the shemesh, and the yarei’ach, and the kokhavim, even all the tz’va HaShomayim, shouldest be driven to hishtachaveh (bow down, worship) them, and serve them which Hashem Eloheicha hath divided unto kol HaGoyim under kol HaShomayim.

20 But Hashem hath taken you, and brought you forth out of the iron furnace, even out of Mitzrayim, to be unto Him an Am Nachalah (a people of inheritance), as ye are yom hazeh.