The Red Hart is a domesticated animal which can be used as a mount in Dragon Age: Inquisition. The Red Hart is available as part of the DLC that comes with Dragon Age: Inquisition Deluxe Edition and Dragon Age: Inquisition Inquisitor's Edition.
Navigate the perilous, living world atop this great-horned beast.
You must first initiate the quest Horses for the Inquisition and complete In the Saddle quest, before you can complete the Red Hart mission on the war table (Orlais) to unlock this mount. The mission takes no time to complete; the Hart will be immediately delivered to your stables upon completion.