19 transmog appearances and 1 mount, pet or toy drop in The Bastion of Twilight.
Battleplate of the Apocalypse×2Plate Chest
Coil of Ten-Thousand Screams×2Mail Waist
Hands of the Twilight Council×2Cloth Hands
Helm of Maddening Whispers×2Plate Head
Kilt of the Forgotten Battle×2Mail Legs
Membrane of C'Thun×2Leather Head
Shackles of the End of Days×2Plate Wrist
Shalug'doom, the Axe of UnmakingTwo-Hand
Treads of Hideous Transformation×2Leather Feet
Twilight's HammerOne-Hand
Uhn'agh Fash, the Darkest BetrayalOne-HandSign in with Battle.net to see which of these appearances and collectibles you already have, and which of your characters can still loot Cho'gall this reset.