Gul Hadar was an officer of the Cardassian High Command.
In 2363, Hadar was a guest invited to the Bajoran Center for Science on Bajor for a viewing of Odo. Hadar could stop talking about Odo's amusing "Cardassian neck trick". In fact, he wanted to send Odo out to entertain the troops, whereas, Gul Dukat had other intentions in mind for the changeling. (DS9: "Necessary Evil")