Argent Charger is a mount for paladins only, acquired from the Argent Tournament.
To get the "Crusader Title" that is required for this Mount, you will need:
Exalted with SilvermoonExalted with Sen'jin
Exalted with ThunderbluffThis will give you the titles of: "of Silvermoon", "of The Undercity", "of Orgrimmar", "of Sen'jin", "of Thunderbluff", "Ambassador".
Kindly Reminder:Possible account termination when using illegal leveling or illegally obtained gold.