Serpentine Sash

Dropped by 8

• Colossus of Zora level 63 9.1% 15740
• Nefarian level 63 1.3% 11583
• Onyxia level 63 1.3% 10184
• Ragnaros level 63 1.3% 11502
• Ragnaros level 63 1.3% 11502
• Korrak the Bloodrager level 62 0.9% 12159
• Lieutenant Vol'talar level 59 0% 13144
• Nefarian level 63 0% 11583

Dropped by, from a shared table 40+

• Azuregos level 63 63107
• Azuregos level 63 6109
• Barkskin Den Watcher level 62 61346
• Barkskin Ursa level 62 61342
• Barkskin Windtalker level 62 61347
• Captain Rothynn level 61 60608
• Colossal Anubisath Warbringer level 62 15743
• Commander Andreon level 61 91919
• Darkflame Imp level 61 62018
• Disrupted Arcane Elemental level 63 61949
• Dragonmaw Mindslave level 61 61889
• Duskfang Creeper level 63 61935
• Elder Growlheart level 62 61348
• Forgotten Echo level 61 62607
• Ima'ghaol, Herald of Desolation level 63 62606
• Imperial Qiraji Destroyer level 63 15744
• Infernal Destroyer level 63 62017
• Infinite Rift-Lord level 62 65105
• Lieutenant General Nokhor level 63 15818
• Lord Kazzak level 63 12397
• Lord Kazzak level 63 63108
• Mana Stalker level 62 61354
• Qiraji Lieutenant General level 63 15757
• Ravenous Strigoi level 61 91910
• Risen Construct level 61 10488
• Risen Warrior level 61 10486
• Runic Construct level 61 60596
• Shadeflayer Goliath level 61 61533
• Shadeflayer Troll level 61 61367
• Shadowbane Alpha level 63 61191
• Skitterweb Venomfang level 62 61208
• Speaker Gan'hota level 63 61361
• Spectral Teacher level 61 10500
• Spectral Worker level 62 61934
• Supreme Anubisath Warbringer level 62 15758
• Temporal Dust level 61 61317
• The Duke of Zephyrs level 62 15220
• Warbringer Overseer level 63 62019
• Warlord Hanzento level 63 61360
• Withermaw Shaman level 62 62871

Only the first 40 are listed.

Found in 1

• Solid Chest 0% 153454

Contained in 3

• Thorium Lockbox level 2 0.4% 5759
• Chest of Spoils level 1 0.2% 20602
• Sack of Spoils level 1 0.1% 20601