ArachnoMod — The Netherite Octoarachnopod

Somewhere in your world, a spider is walking toward you.

ArachnoMod adds a single, relentless, procedurally animated spider that stalks players across the world. Its eight legs are solved in real time with FABRIK inverse kinematics and drawn entirely with vanilla BlockDisplay entities. Every step is calculated, not pre-baked, so it scuttles believably over any terrain.

But this isn't a tech demo for movement physics. It's a hunter.

🕷️ The Hunt

• It grows with distance. Far away it towers over the trees — a horror on the horizon. As it closes in, it shrinks back down to a more "normal" (but still deadly) size. Close = small, far = huge.
• It charges. The farther away it is, the faster it moves — barreling toward you at terrifying speed across open ground, then easing back to a stalk as it reaches you.
• It hunts the nearest player within a 64-block radius, and won't stop until it's dead or you are.
• 1000 HP. This is no ordinary mob. Bring friends, bring gear, or bring a plan.
• A 6-heart bite. Getting caught hurts.
• One at a time. Only a single spider roams the world at once. Kill it, and a new one returns on its own 5–30 minutes later.

🥚 Encountering it

You don't have to do anything — one spawns on its own and comes looking. But if you want to summon one yourself, grab the Netherite Octoarachnopod spawn egg from the Spawn Eggs creative tab.

It dies like any other mob. Beat it down, and it goes poof.

📦 Requirements

• Minecraft 1.21.1
• NeoForge 21.1.x
• Kotlin for Forge (REQUIRED. Install it alongside this mod)

🙏 Credits

This mod stands entirely on the shoulders of Heledron (TheCymaera/Cymaera), whose original procedural-spider plugin is the heart of everything you see here. All of the inverse-kinematics leg animation, gait, and BlockDisplay rendering brilliance is theirs. I just built a hostile-mob experience on top of it.

Please go support the original creator:

• 🔧 Original plugin (GitHub): https://github.com/TheCymaera/minecraft-spider
• 🎬 Demo video: https://www.youtube.com/watch?v=Hc9x1e85L0w
• 📺 Heledron's YouTube channel: https://www.youtube.com/@heledron

Ported to NeoForge and turned into a hunting mob by iR3DN4X.

If anyone finds any bugs/glitches/suggestions, please report them back to me in the comments!