Speak, and say, Thus saith the Lord GOD; Behold, I am against thee, Pharaoh king of Egypt, the great dragon that lieth in the midst of his rivers, which hath said, My river is mine own, and I have made it for myself.
The great dragon - Hebrew х taniym (H8577)], any large aquatic animal, here it is the crocodile, which on Roman coins is the emblem of Egypt.
That lieth - restest proudly secure.
In the midst of his rivers - the mouths, branches, and canals of the Nile, to which Egypt owed its fertility.