How do you reconcile Genesis 7:21-22
21 And all flesh died that moved upon the earth, both of fowl, and of cattle, and of beast, and of every creeping thing that creepeth upon the earth, and every man:
22 All in whose nostrils was the breath of life, of all that was in the dry land, died.
It doesn’t say almost all, God’s Word says “every” and “all”. That’s plain enough for me.
Maybe Noah took 2 Nephilim on the ark? Nah...
Noah and his sons were pure, but all flesh was corrupted.
A possible answer is that the wives that Noah’s sons chose to take with them had a genetic component of Nephilim.
Thus, some of Noah’s grandchildren could have become Nephilim.
At least that is one theory that I have heard from bible scholars.
Yes, I also believe every animal on the face of the earth perished in the Flood.
That said, theologians have many theories on why there were giants after the flood, but Scripture doesn't explain it clearly. As was suggested by another Freeper on this thread, the DNA of the sons' wives might have been tainted.
But, however it happened, there were giants (descendants of the Nephilim and the Fallen Angels) after the Flood.