When someone suffers from delusions of grandeur, believes they have jungle cat blood, DNA from a Greek god and special magical powers in bed, all whilst behaving as if they were totally invincible.
Tom: “Did you hear about Harry?”
Fred: “No man. What did he do now?”
Tom: “The dude’s totally gone sheen. Last week he was out partying like a rock star, trashing hotel rooms and sleeping with strippers.”