21 transmog appearances and 1 mount, pet or toy drop across 4 bosses.
Cinnabar ShouldersPlate Shoulder
Crackling Geode MaceOne-Hand
Dolomite Adorned GlovesCloth Hands
Fist of Pained SensesOne-Hand
Crystalpowder AmiceCloth Shoulder
Deep Delving GlovesLeather Hands
Hematite Plate GlovesPlate Hands
Quicksilver BladeOne-Hand
Skin of StoneCloth Back
Wand of Dark WorshipRanged
Belt of the RingwormPlate Waist
Elementium Scale BracersMail WristHeavy Geode MaceOne-Hand
Sword of the Bottomless PitTwo-Hand
Cowl of the Unseen WorldMail Head
Darkling StaffTwo-Hand
Elementium FangOne-Hand
Helm of Numberless ShadowsLeather Head
Prophet's ScepterHeld In Off-hand
Slippers of the Twilight ProphetCloth FeetSign in with Battle.net to see which of these appearances and collectibles you already have, and which of your characters can still loot each boss this reset.