LootBags

LootBags adds loot bags to Minecraft that pull their contents from the game's loot tables. It was designed mainly so skyblock packs could still hand out dungeon loot, and it also supports configurable custom bags.

Available for Forge across Minecraft 1.7.10 - 1.12.2. The author no longer develops it, but it stays functional and is still part of many older modpacks.

Planning a classic skyblock world? Add it to your Minecraft server with a single click in the panel.