The 
Containment Jar is a block in Ars Nouveau that stores a mob inside it, shrunk down so it fits in a single block. It’s mostly used for moving mobs around or keeping them as decoration, but a lot of mobs keep doing their normal thing while they’re in the jar, so you’re able to milk a Cow, shear a Sheep or trade with a Villager without them ever wandering off.
Getting a mob into a Containment Jar isn’t done by hand, as it needs the 
Ritual of Containment on a 
Ritual Brazier. Once it’s in there, the jar can be picked up and placed somewhere else with the mob still inside, which is one of the easiest ways of moving Villagers or other awkward mobs across your base.
Crafting the Containment Jar
A Containment Jar is crafted from three 
Archwood Slabs along the top row and five 
Glass, with the middle of the jar left empty. It’s a fairly cheap recipe, so it’s worth making a few at once if you’re planning on catching more than one mob.
The Ritual of Containment tablet is crafted from a 
Vexing Archwood Log, a 
Manipulation Essence and three 
Glass Bottles. You’ll also need a Ritual Brazier to perform it on, which is made from an 
Arcane Pedestal, a 
Source Gem Block and three 
Gold Ingots.
Catching a Mob
To catch a mob, you’ll need to place the empty Containment Jars close to the Ritual Brazier, put the Ritual of Containment on it and start it with an empty hand. The ritual then checks every 3 seconds for a mob within 5 blocks of the Ritual Brazier, and puts it into one of the empty jars nearby, so it’s easiest to lead the mob right up next to it first.
The first mob is free, but after that the ritual needs 500 Source for each extra capture, which it takes from a 
Source Jar nearby. Players can never be caught, and neither can familiars, although it isn’t only mobs that work. Dropped items, boats, Armor Stands, Ender Pearls and even lightning bolts are all able to go into a jar.
To let a mob back out, you’ll need to cast Dispel on the jar, and the mob appears on top of it. The only exception is the Ender Dragon, which can be caught but can’t be released again. Placing a 
Note Block on top of a jar also makes it play the sound of whatever mob is inside, which is a nice touch for decoration.
What Mobs Do in a Jar
A lot of mobs still work while they’re inside a Containment Jar, and some of them turn the jar into something genuinely useful. This is where most of the jar’s value comes from, as you’re able to build very compact farms with one mob per jar, and the table below covers the ones that do something.
| Mob | What it does in a jar |
|---|---|
| Chicken | Lays  Eggs every so often |
| Cow | Can be milked with a  Bucket |
| Sheep | Can be sheared with  Shears, and eats grass under the jar to regrow its wool |
| Mooshroom | Gives  Mushroom Stew with a  Bowl, and can be sheared back into a Cow |
| Villager | Can be traded with, and restocks its trades over time |
| Piglin | Barters when you throw Gold Ingots at the jar |
| Allay | Collects items within 5 blocks and puts them into a container next to the jar |
| Sniffer | Digs up ancient seeds now and then |
| Armadillo | Sheds Scutes now and then |
| Frog | Eats Slimes that come close |
| Panda | A baby Panda sneezes out Slimeballs |
| Blaze | Makes the jar a light source, at full brightness |
| Glow Squid | Makes the jar a light source |
| Pufferfish | Puffs up when mobs are nearby, giving off a redstone signal |
| Cat | Gives a redstone signal while its owner is online, and brings gifts when they sleep nearby |
| Snow Golem | Throws a snowball when the jar is powered with redstone |
| Breeze | Fires a Wind Charge when the jar is powered with redstone |
| Ender Dragon | Gives  Dragon’s Breath when used with a Glass Bottle |
| Wither | Mobs that die within 4 blocks drop a  Wither Rose, and powering the jar breaks the blocks around it |
| Elder Guardian | Gives players within 50 blocks Mining Fatigue while the jar is powered |
On the 1.20.1 version, the Cat, Sniffer and Snow Golem don’t do anything special inside a Containment Jar, and the Armadillo and Breeze aren’t in that version of Minecraft at all. The rest of the mobs in the table work the same way.
The Allay is probably the most useful one for automation, as it’ll pick up items around the jar and drop them into a 
Chest placed next to it. Giving the jarred Allay an item makes it only collect that item, and it also respects any filters on the container it’s putting things into, so it works a lot like a small item magnet.
Containment Jars and Drygmys
Containment Jars also count as mobs for a 
Drygmy Henge within 10 blocks, which is one of the best reasons to make a few of them. Since a Drygmy produces more items for every different type of mob it can see, a row of jars with a different mob in each one gives you a very compact mob farm that never has any mobs wandering around.
The mob in the jar is never hurt by the Drygmys either, so you’re able to keep something like a Blaze or a Wither Skeleton in a jar and get its drops without having to deal with it. It’s worth using the 
Dominion Wand on the Drygmy Henge as well, which makes it only count the jars and ignore anything else walking past.
Frequently Asked Questions
Place an empty Containment Jar next to a Ritual Brazier, and perform the Ritual of Containment with the mob within 5 blocks of the brazier. The first mob is free, and every capture after that costs 500 Source.
Cast Dispel on the Containment Jar, and the mob will appear on top of it. The Ender Dragon is the only mob that can’t be released once it’s caught.
Yes, a Villager in a Containment Jar can be traded with the same as normal, and its trades still restock over time. That makes it easy to move Villagers around, or build a very small trading hall.
Yes, any Containment Jar within 10 blocks of a Drygmy Henge counts as a mob for the Drygmys, so a row of jars with different mobs is one of the best Drygmy setups you’re able to make.
