Bat Traveler's Backpack: Where to Find It and What It Does
The Bat Traveler's Backpack is a themed backpack found as loot in mineshafts and dungeons — a collectible design rather than a crafted starter pack.
Getting the Bat Backpack
Unlike the basic backpack you craft at a table, the Bat Traveler's Backpack is obtained by exploration: it generates as loot in mineshaft and dungeon chests. If you would rather build one, it is assembled from a Standard Traveler's Backpack plus the bat-themed materials, the same way the mod's other themed backpacks are made.
What It Does
The Bat backpack is a cosmetic, collector variant — it does not grant an activated special ability the way some themed backpacks do (the Lapis, Redstone, Cactus, Sponge and Cake backpacks each carry a unique tooltip effect). Instead it gives the full standard Traveler's Backpack toolkit:
- A large built-in inventory for hauling loot out of the caves where you find it.
- Two fluid tanks for carrying water, lava, or other fluids, filled and drained through the
Hose Nozzle. - Tool slots and a built-in sleeping bag, so you can rest without placing a bed.
Upgrading and Using It
Treat the Bat backpack like any other in the mod:
- Raise its storage tier with an
Iron Tier Upgrade, then 
Gold Tier Upgrade, 
Diamond Tier Upgrade, and finally a 
Netherite Tier Upgrade (the netherite step is applied at a smithing table) to expand its inventory. - Equip it in your body slot, or place it as a block to open its inventory and tanks, then pick it back up to keep travelling.
- Because it starts as dungeon loot, it is a handy early find on a mining trip — offload cobblestone and ore into it right away and top up its tanks from any water you pass.
If you specifically want a backpack with an active effect, pick one of the ability backpacks instead; the Bat backpack's appeal is its look and the convenience of finding a full-featured backpack underground.
Upgrading without losing the design
Tier upgrades are their own recipe category — 44 of them — and they all share one shape: 
leather, the backpack you already own, and a tier upgrade item. The result is the same backpack at a higher tier.
That is the important part. Upgrading a Bat Traveler's Backpack returns a Bat backpack, not a generic one, so the appearance and any themed behaviour survive the upgrade. There is no reason to hold off on using a themed pack early for fear of replacing it later.
How many designs there are
The mod carries 46 backpack recipes alongside those 44 upgrades, covering themed packs from Bat and Bee to Blaze and 
Bookshelf. Between them and the 48 ordinary crafting recipes, nearly the whole mod is backpacks and the parts that go into them.
What the upgrade costs
Leather is the constant in every upgrade recipe, so a leather supply is the practical limit on how many packs you can raise a tier — the tier upgrade item itself is the rarer half, but leather is what you will run out of first when upgrading a collection.
Version parity
The backpack and upgrade lists are identical on 1.21.1 and 1.20.1 (46 and 44 respectively), with only one crafting recipe differing between the lines.
Hose