Pharaoh’s Claim To Be God
It was an expression of ‘ananiyat’. The same ‘ananiyat’ that Iblees showed in front of God and blinded Pharoah’s senses as well. He knew deep down that he was the creation of God and confessed his faith in Allah when he was drowning.
Hubris, ego, arrogance. Actually its one of the words for which no alternative in English exists which completely portrays its meaning.