Dagon Blackgard is an unseen character in Game of Thrones. He is deceased when the events of the series begin and is not expected to appear in the series. Dagon was the secondborn son of Trovar Blackgard, the Lord Paramount of the Ashlands. He was strangled to death by House Keller assassins during the Fourth Border Wars.
He is remembered by Trevyr Blackgard for being mostly silent and intricate, and for his excellent use with a bow. He and Trevyr held a strained relationship, being mostly away from home due to the war.