The best place to farm Pattern: Bottomless Bag is Silithus, where Hive'Regal Hive Lord (level 59-61) drops it at 0.0%. That is the vanilla 1.12 chance, not yet confirmed in Forever. 12 sources are ranked below by drop chance.
Best zones:
| Zone | Sources | Best source | Level | Drop% |
|---|---|---|---|---|
| Blasted Lands | 1 | Lord Kazzak | 63+ | 0.1% |
| Feralas | 1 | Dreamroarer | 62+ | 0.1% |
| Silithus | 1 | Hive'Regal Hive Lord | 59-61+ | 0.0% |
| Ruins of Ahn'Qiraj | 1 | Hive'Zara Wasp | 61+ | 0.0% |
| Molten Core | 3 | Firelord | 61-62+ | 0.0% |
| Zul'Gurub | 1 | Gurubashi Berserker | 62+ | 0.0% |
| Ahn'Qiraj | 2 | Qiraji Mindslayer | 61+ | 0.0% |
| Blackrock Spire | 1 | Blackhand Iron Guard | 60-61+ | 0.0% |
| Blackwing Lair | 1 | Death Talon Hatcher | 61+ | 0.0% |

- Lord Kazzak 35.6, 74.4
All sources, by drop chance:
| Source | Level | Zone | Spawns | Side | How | Drop% | Map |
|---|---|---|---|---|---|---|---|
| Lord Kazzak(elite) | 63+ | Blasted Lands | 1 | Drop | 0.1% | map | |
| Dreamroarer(elite) | 62+ | Feralas | 1 | Drop | 0.1% | map | |
| Hive'Regal Hive Lord(elite) | 59-61+ | Silithus | 34 | Drop | 0.0% | map | |
| Hive'Zara Wasp(elite) | 61+ | Ruins of Ahn'Qiraj | 31 | Drop | 0.0% | map | |
| Firelord(elite) | 61-62+ | Molten Core | 18 | Drop | 0.0% | map | |
| Gurubashi Berserker(elite) | 62+ | Zul'Gurub | 18 | Drop | 0.0% | map | |
| Lava Annihilator(elite) | 61-62+ | Molten Core | 18 | Drop | 0.0% | map | |
| Qiraji Mindslayer(elite) | 61+ | Ahn'Qiraj | 18 | Drop | 0.0% | map | |
| Blackhand Iron Guard(elite) | 60-61+ | Blackrock Spire | 17 | Drop | 0.0% | map | |
| Qiraji Slayer(elite) | 61+ | Ahn'Qiraj | 14 | Drop | 0.0% | map | |
| Firewalker(elite) | 61-62+ | Molten Core | 13 | Drop | 0.0% | map | |
| Death Talon Hatcher(elite) | 61+ | Blackwing Lair | 11 | Drop | 0.0% | map |
Drop% is the rate recorded in Forever once a source has been looted ten times; a greyed figure is the vanilla 1.12 chance from the world data (vanilla reference — from the 1.12 world data, not yet confirmed in forever). Spawns counts the source's spawn points in the world data. "Side" names which side can kill the NPC when the other finds it friendly. The lead picks the best chance among sources that are not a rare spawn and have at least three spawn points.