Alex's Caves Eruption Update | Volcano Cave Mod

The Eruption Update is the first major content drop for Alex's Caves, a mod that buries six rare cave biomes under the Overworld. It expands the Primordial and Toxic caves with volcanoes, two boss-scale creatures, fresh weapons, and a stack of enchantments that lean hard into the prehistoric and radioactive themes. If you have already spent hours hunting for an Underground Cabin, this is the update that gives you a reason to go back underground.

Primordial Caves: Volcanoes and the Luxtructosaurus

The centerpiece of the Primordial Caves is the Volcano, a huge lava pool with a blackstone spire rising from the middle. It sits there harmlessly until you decide to wake it up.

Triggering an Eruption

To set the volcano off, craft an Ominous Catalyst from Heavy Bones and an Amber Curiosity, then throw it into the caldera. The sky darkens, lava rises, and the eruption begins.

The Luxtructosaurus Boss Fight

The eruption summons the Luxtructosaurus, a dinosaur the size of a small mountain. It hits hard, shrugs off ordinary weapons, and will stomp the ground hard enough to wreck trains and terrain around it. Bring real armor and a plan, because trading blows head-on is a quick way to lose your kit. When it finally falls, it drops Tectonic Plates, the core material for several of the best items in the update.

Atlatitans: Friendly Rideable Mounts

When the Luxtructosaurus is defeated, Atlatitans spawn nearby. These are calmer relatives of the boss, and you can tame them with Serene Salad. A tamed Atlatitan makes an excellent mount for caving and combat thanks to a stomp attack that flattens terrain in its path.

Tectonic Plates have a second use too. You can give the dinosaurs roaming these caves new eruption-themed skins, a nice cosmetic payoff after the fight that produced them.

Toxic Caves: Hatching a Tremorzilla

The Toxic Caves get their own headline creature. Tremorzilla eggs are a new item you can incubate here, and they have one strange rule. They only hatch when set off by a nuclear explosion.

Raising and Riding a Tremorzilla

A baby Tremorzilla is tamed with a Waste Drum. Feed it nuclear bombs to speed up its growth, and once it is fully grown you can ride it. A grown Tremorzilla bites, swipes with its claws, and fires radioactive laser beams, making it one of the most destructive pets you can raise in the mod.

New Weapons and Enchantments

Alongside the two big creatures, the Eruption Update ships a roster of weapons and enchantments themed around the Primordial and Toxic biomes.

The Extinction Spear is the standout. It summons dinosaur spirits to fight alongside you, so a single swing can turn a bad situation into a crowd-clearing one.

Enchantments let you tune each weapon further. The Radioactive Raygun, with the Gammaray enchantment, turns blue and deals bonus radiation damage to anything it hits.

The Orthall Lance pairs with the Tsunami enchantment to summon waves out of the Abyssal Depths, and the Enveloping Bubble enchantment lets you suffocate enemies instead of trading blows.

How to install:

Requires Forge or NeoForged, plus the Citadel dependency. Drop the jar in your mods folder. See the full how to install Minecraft mods guide for the step-by-step.

Read More About Alex's Caves

For the main download and a full breakdown of all six cave biomes, visit our Alex's Caves mod page. The Eruption Update is built into the current version of the mod, so once it is installed you have everything covered here.

Frequently Asked Questions

How do I trigger a volcano eruption?

Craft an Ominous Catalyst from Heavy Bones and an Amber Curiosity, then throw it into the volcano's caldera inside a Primordial Cave. The eruption summons the Luxtructosaurus boss, so prepare your gear first.

Can the Tremorzilla be tamed?

Yes. A baby Tremorzilla is tamed with a Waste Drum. Feed it nuclear bombs to grow it faster, and once it is fully grown you can ride it into combat and fire its radioactive laser beams.

Do I need any other mods installed?

Yes. Alex's Caves requires the Citadel mod as a dependency, and you need a compatible loader installed before you drop the mod jar into your mods folder.

Is Alex's Caves still being maintained?

The last official Alex's Caves release landed in October 2024, and the Eruption Update itself shipped in early 2024. Check the project page for the current status before you build a world around it.