29 transmog appearances and 1 mount, pet or toy drop in Ulduar.
Ancient Iron HeaumePlate Head
Belt of Colossal RagePlate Waist
Belt of the Crystal TreeLeather Waist
Belt of the Iron ServantMail Waist
Boots of the Petrified ForestLeather Feet
Circlet of True SightMail Head
Cloak of the Iron CouncilCloth Back
Drape of Mortal DownfallCloth Back
Drape of the LitheCloth Back
Fang of OblivionOne-Hand
Greaves of Iron IntensityPlate Feet
Greaves of Swift VengeanceMail Feet
Handguards of the EnclavePlate Hands
Iron-Studded MantleMail Shoulder
Leggings of Swift ReflexesLeather Legs
Overload LegwrapsCloth Legs
Perilous BiteOne-Hand
Phaelia's Vestments of the Sprouting SeedLeather Chest
Raiments of the Iron CouncilCloth Chest
RaptureTwo-Hand
Rune-Etched NightbladeOne-Hand
Runed Ironhide BootsLeather Feet
Runeshaper's GlovesMail Hands
Runetouch WristwrapsCloth Wrist
Shoulderpads of the IntruderLeather Shoulder
Steelbreaker's EmbracePlate Chest
Stormrune EdgeTwo-Hand
StormtipOne-Hand
The MasticatorOne-HandSign in with Battle.net to see which of these appearances and collectibles you already have, and which of your characters can still loot The Assembly of Iron this reset.