What the Bible says about Giants

Giants are the offspring of the sons of god and the daughters of men.

There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men. Genesis 6:4

Some of them managed to survive the flood.

And there we saw the giants ... And we were in our own sight as grasshoppers, and so we were in their sight. Numbers 13:33

The people is greater and taller than we ... we have seen the sons of the Anakims there. Deuteronomy 1:28

a people great, and many, and tall, as the Anakims ... which also were accounted giants. Deuteronomy 2:10-11

A land of giants: giants dwelt therein in old time. Deuteronomy 2:20

Luckily, "the Lord destroyed them."

A people great, and many, and tall, as the Anakims; but the LORD destroyed them. Deuteronomy 2:21

But, apparently, God didn't kill them all.

Only Og king of Bashan remained of the remnant of giants; behold his bedstead ... nine cubits was the length thereof. Deuteronomy 3:11

A people great and tall, the children of the Anakims. Deuteronomy 9:2

And the coast of Og king of Bashan, which as of the remnant of the giants. Joshua 12:4

The valley of the giants Joshua 18:16

Until, Goliath, the last of the giants was finally killed.

Goliath, of Gath, whose height was six cubits and a span. 1 Samuel 17:4