The firstborn twin of Isaac and Rebekah. He came out red and hairy like a garment. He was the natural heir, the strong one, the favorite of his father because "he had a taste for wild game."
Esau was a man of action and appetite. He lived by his bow. He was comfortable in the wild, unlike the "tent-dwelling" Jacob. His identity was wrapped up in his physical prowess and ability to provide food.
He was formed by entitlement. As the firstborn and the father's favorite, he likely assumed the blessing was his by right, regardless of his character or choices.