20 transmog appearances and 1 mount, pet or toy drop in Siege of Orgrimmar.
Belt of the Broken PactCloth Waist
Chestguard of Relentless TyrannyMail Chest
Chestplate of Fallen PassionPlate Chest
Cord of Black DreamsLeather Waist
Cowl of Smoking DreamsMail Head
Ebon Ritual HoodCloth Head
Greathelm of the WarchiefPlate Head
Hopeglow SpauldersLeather Shoulder
Horned Mace of the Old OnesOne-Hand
Kor'kron Elite SkullmaskLeather Head
Kor'kron Spire of SupremacyTwo-Hand
Legplates of Unthinking StrifePlate Legs
Mantle of Looming DarknessPlate Shoulder
Penetrating Gaze of Y'ShaarjMail Head
Revelations of Y'ShaarjHeld In Off-hand
Seal of Karmic ReturnLeather Waist
Shoulderguards of Intended PowerMail Shoulder
Spaulders of the Fallen WarchiefPlate Shoulder
Tusks of MannorothPlate Shoulder
Xal'atoh, Desecrated Image of GorehowlTwo-HandSign in with Battle.net to see which of these appearances and collectibles you already have, and which of your characters can still loot Garrosh Hellscream this reset.