Edgar is a giant alien arthropod cockroach monster with only one thing on his mind, food.
He likes big meals so that usually means swallowing his prey whole and alive. His capacity for prey is gigantic, and he really doesn't care about whoever or whatever he eats. The only reason he'd leave someone alive is to get more food.
He finds any notion of romance repulsive.
He does get offended easily however, making mention of him being compared to cockroach.