LootBags mod adds bags that drop other items. It adds an item that contains random loot from any of the vanilla dungeon loot lists (dungeons, strongholds, mineshafts, temples, and blacksmiths). This bag can be found dropped by monsters, passive mobs, and players or in vanilla worldgen chests.
It is heavily configurable through its two config files, in which the wiki on the GitHub contains more information on using the configs. By default, the mod is configured for a total of 9 bags, 5 typical bags, and 4 “secret” bags which only spawn in certain conditions. The typical bags drop portions of the vanilla world gen loot tables, with rarer bags relating to more consistent rare loot.
The mod includes a recycler block which will consume items that are dropped by loot bags, and once a certain value (determined by which bag the recycler is configured to create and a scaling factor) it will create a new lootbag that can be pulled out by any typical modded method of removing items from an inventory. Items can similarly be pumped into the block.