There are a number of transmogs/appearances in the game that appear to be unobtainable. I probably have close to 1000 hours in the game, 600+ exclusively on barbarian and druid, have leveled 12+ characters to 100, completed the campaign and all other content available multiple times, yet still have numerous transmogs still missing. Speaking with other players who similarly have a lot of playtime, the following items should be looked at for possible bugs or unobtainable appearances:
Doom Hammer - Legendary Two-handed Mace (Item ID 592302)
Battle Axe - Axe (Item ID 459950) (there is another appearance with the same name that is obtainable)
Broad Axe - Axe (Item ID 459949) (there is another appearance with the same name that is obtainable)
Combat Hatchet - Axe (Item ID 784817)
Twin Axe - Axe (Item ID 459948)
Axe - Axe (Item ID 1046306)
Snake Axe - Legendary Axe (Item ID 1267098)
Ravager - Legendary Axe (Item ID 1306998)
Punisher - Mace (Item ID 784853)
Leaden Mace - Mace (Item ID 784740)
Flanged Mace - Mace (Item ID 459997)
Hammer - Mace (Item ID 459996)
Dread Glaive - Legendary Polearm (Item ID 592304)
It’s also maybe worth noting that when looking at the item values in detail, I noticed for legendary one-handed axes for example, all of the axes that don’t seem to drop and therefore you can’t get the transmog appearance, have a “dwFlags” value of 29834. Whereas all of the legendary one-handed axes that currently do drop and that you can get the transmog appearance for, have a dwFlags value of 29832. All other values for these legendary one-handed axes are identical. There is also a “bIsTransmog” value and these are all set to “true” for every one of these items in question, which means the item gives the transmog appearance upon salvage.
This is consistent for all items. For example, all of the legendary two-handed maces that you can obtain in the game have the same dwFlags value of 29832, yet the Doom Hammer, which no one can seemingly get, has a dwFlags value of 29834. The same is true for ALL legendary items (29832 = obtainable, 29834 = unobtainable). Is this dwFlags some kind of drop weighting? If so, something is clearly wrong as no one can find the “29834” items.
For some of the blue/magic rarity transmogs, you can only get them by finding an item with one class, such as finding an Augur focus on a Sorcerer, then salvaging that Augur with a Necromancer, to acquire the Necromancer version (identical appearance), called Sinner’s Skull. The Sinner’s Skull NOR the Augur focus can drop for a Necromancer, for whatever reason, yet the transmog appearance is for a Necromancer ONLY. This makes no sense but see below for a few transmogs that can be obtained this way. All other grey/blue items listed here are unobtainable and just like how there are different dwFlags values for the legendary items, determining which items drop and which don’t, the same is true for grey/blue items as well.
The following are not 100% confirmed to be unobtainable but none of the people I spoke to have these transmogs, so it is extremely likely you can not get these currently. Same as above, all of these items have the dwFlags value matching items that can not drop:
Skeletal Protector - Legendary Shield (Item ID 1307045)
Grisly Trophy - Legendary Wand (Item ID 1266266)
Death’s Reach - Legendary Two-handed Scythe (Item ID 1307041)
Hell’s Fang - Legendary Two-handed Scythe (Item ID 1307043)
Obsidian Totem - Legendary Totem (Item ID 1267242)
Shamanistic Staff - Legendary Druid Staff (Item ID 1306958)
Runic Staff - Legendary Druid Staff (Item ID 1306956)
Corruption - Legendary Sorcerer Staff (Item ID 1306653)
Doom Harbinger - Legendary Sorcerer Staff (Item ID 1306651)
Swift Death - Legendary Crossbow (Item ID 1267257)
Silver Filigree Bow - Legendary Bow (Item ID 1267248)
Death’s Dirk - Legendary Dagger (Item ID 1267003)
Rebirth Edge - Legendary Dagger (Item ID 1267078)
Thief’s Shank - Dagger (Item ID 459944)
Kris - Dagger (Item ID 459945 - Has been obtainable previously, might not be currently)
Kard - Dagger (Item ID 459943 - Confirmed that it can be acquired by receiving “Mohlon’s Fang” dagger from Act 5 “Cold Blood” quest, then salvaged with a Rogue)
Tecpatl - Dagger (Item ID 495769 - Can be acquired by finding a stiletto on a Rogue, then salvaging the stiletto with a necromancer)
Scorning Mask - Focus (Item ID 459857)
Decorated Skull - Legendary Focus (Item ID 1266836)
Death Charm - Focus (Item ID 494591)
Vial of Power - Focus (Item ID 459859)
Tome - Focus (Item ID 459858)
Sinner’s Skull - Focus (Item ID 494592 - Can be acquired by finding an Augur on a Sorcerer, then salvaging the Augur with a necromancer)
Prophetic Urn - Focus (Item ID 790584 - Can be acquired by finding a Keepsake on a Sorcerer, then salvaging the Keepsake with a necromancer)
Morningstar - Mace (Item ID 459998 - Can likely be acquired by receiving “Borza’s Bonecrusher” from the side quest “A Pound of Flesh,” and then salvaging on a barbarian or druid - need confirmation but very likely)
I guess it’s possible these are all for future content but many of them have been in the game files since launch, so it does beg the question are these inactive/scrapped? Are they for future content (season/expansion), or are they supposed to drop but are bugged? I’m a completionist and one side-activity I like to do is hunt down all cosmetics and achievements in-game. So it sucks seeing my wardrobe with dozens of “lock” icons, implying there are more transmogs to be found.