Dagon was originally an Assyro-Babylonian fertility god who evolved into a major northwest Semitic god, reportedly of grain (as symbol of fertility) and fish and/or fishing (as symbol of multiplying). He was worshipped by the early Amorites and by the inhabitants of the cities of Ebla (modern Tell Mardikh, Syria) and Ugarit (modern Ras Shamra, Syria) (which was an ancient city near the Mediterranean containing a large variety of ancient writings and pre-Judeo-Christian shrines). He was also a major member, or perhaps head, of the pantheon of the Biblical Philistines.
His name appears in Hebrew as דגון (in modern transcription Dagon, Tiberian Hebrew Dāḡôn), in Ugaritic as dgn (probably vocalized as Dagnu), and in Akkadian as Dagana, Daguna usually rendered in English translations as Dagan.
Read more about Dagon: Etymology, Non-Biblical Sources, In Biblical Texts and Commentaries, Marnas, Fish-god Tradition