15 Insane Things People Built With Claude Mythos in 48 Hours
V8 engines. Humanoid robots. Minecraft clones. Full RPGs. This is what the model drop actually looked like - from the people who pushed it hardest.
Claude Mythos just dropped. And within 48 hours, X was on fire.
Not from Anthropic’s launch post.
From the people who immediately opened a blank prompt and asked it to do something insane.
→ A V8 engine CAD model in 10 minutes.
→ A Minecraft clone with background music.
→ A humanoid robot designed from scratch in 2 hours.
→ A QDD actuator with collision validation.
→ A Three.js RPG where you blow stuff up with a bazooka.
And most of these people weren't developers. They were just the first ones to stop waiting and start typing.
I went through every Mythos use case posted in the first 48 hours and pulled the 15 that actually made me stop scrolling.
By the time you finish this issue, you'll know exactly which category of work Mythos dominates - and you'll have 15 real examples to reference the next time someone asks you whether AI can actually build something serious.
You go from curious to informed.
That's the only upgrade that matters right now.
By the end of this issue, you’ll get a curated swipe file of all 15 examples with direct links - so you can study what’s now possible and start thinking about what you can build.
Here's everything that happened when people got their hands on Mythos - and what it tells you about what you should be doing with it right now.
You’re the reason this newsletter exists. What AI tool or workflow should I test next? Drop your topic in the comments - the most-requested one becomes the next issue.
I'll be honest - when Mythos dropped, I did what I always do.
I opened it, typed something safe, got a decent result, and moved on.
It wasn't until I saw the V8 engine tweet that I stopped.
Not because of the output. Because of the time. Ten minutes.
I've watched engineers spend weeks on CAD models.
So I went back in and started pushing harder.
Here's what I found.
The 15 Use Cases
1. A Playable Fable-Style Sandbox World
This one is a different category.
Someone ran down the full list of what the Fable game allows: buy every house, evict all tenants, make the whole population homeless, kill every NPC (they repopulate), marry someone in every village, hire the homeless into your businesses.
The list keeps going.
It’s a reminder that sandbox design is a problem of interconnected systems - and Fable 5 can hold all of them at once.
If this is useful, share it with one person who needs it. Takes 10 seconds.
2. Fluid Ink Merging Effect - A Deliberate Stress Test
A Japanese developer specifically designed this prompt to push limits.
They wanted an effect where ink melts together like a fluid - a visual that sits at the intersection of shader logic and aesthetic taste.
They expected it to struggle.
It didn’t.
The output was production-grade, and the design expressiveness caught them off guard.
You can actually interact with it live.
3. An Original Melody - With a Piano Visualizer
Mythos 5 wrote a melody.
And then, apparently because it felt like it, it also built a piano visualizer to go with it.
This use case doesn’t fit neatly into “coding” or “creativity” - it’s both at once.
The person who shared it said they genuinely loved the melody.
That’s a harder result to fake than a working game.
4. Minecraft in HTML - With Background Music
Angel ran a Claude Fable 5 (MAX) Minecraft-in-HTML test.
The result was strong enough that they noted it specifically added background music without being asked.
Cost: approximately $30.
The unsolicited music is the detail that matters here - the model filled in what it decided was missing, not just what was asked.
If this is useful, share it with one person who needs it. Takes 10 seconds.
5. A Humanoid Robot
Jake Fitzgerald ran a longer session this time.
2 hours. 1.4 million tokens.
The output: a humanoid robot design.
This is the kind of token run that starts to look less like a prompt and more like a collaboration.
The result was detailed enough that “absolutely insane” was Jake’s honest reaction - not hype, just what happened.
6. A Website About Itself - Built With Complete Freedom
Aurelien gave Fable 5 one instruction: make a website about yourself, do whatever you want.
The result was something neither expected.
This is the kind of experiment that reveals something about how the model thinks - when there’s no constraint, what does it choose to make?
The answer turned out to be genuinely surprising.
7. A Fully Working V8 Engine CAD Model
Someone handed Fable 5 a single prompt:
“Make me a model of a V8 engine.”
Ten minutes later, they had a fully working CAD model.
Not a sketch. Not a wireframe. A model. CAD has historically required years of software training to navigate the tools. Fable 5 collapsed that entire barrier in one session.
The barrier was never talent. It was tooling. That's gone now.
8. A 1:1 Minecraft Clone
This one has a receipts trail.
WorldofAI ran Claude 5 Fable on MAX for 55 minutes and 52,400 tokens.
The output: a Minecraft clone with multiple biomes, a day/night cycle, ores, and cave systems.
The whole sandbox. Not a demo. Not a proof of concept.
A functional replica.
If this is useful, share it with one person who needs it. Takes 10 seconds.
9. A Realistic Open-World RPG - Running for Mayor of LA
The prompt: “Make a realistic open-world RPG about running for mayor of LA.”
The side quests that emerged were, in the creator’s words, unhinged.
This is the use case that shows something different - it’s not just technical output; it’s narrative design at speed.
World-building, quest logic, character behavior - all in one pass.
10. One-Shot Super Mario Bros (NES)
Every time a new AI model drops, John Savage runs the same test: one-shot Super Mario Bros.
With Mythos Fable 5, he got closer than ever.
This benchmark matters because it’s not just about generating code - it’s about understanding game physics, sprite behavior, input handling, and collision logic simultaneously.
The gap is closing fast.
11. An Open-World RPG in Three.js - With a Bazooka
The prompt was exactly this: “Fable, build me an open-world RPG in Three.js where I get to run around and blow stuff up with a bazooka.”
Dan Greenheck got exactly that.
Playable. Open world. Explosions included.
The model encapsulated the game logic, physics, environment, and UI in a single pass.
Dan’s caption: “Hold my beer.”
12. GTA 6 Built From One Prompt
The prompt was three words: “make gta 6.”
What came back was a playable open-world game.
Obviously not the real GTA 6 - but the fact that a three-word prompt produced a working open-world with that aesthetic is the whole point.
Game studios should be paying attention to how fast the floor is rising under their junior dev teams.
If this is useful, share it with one person who needs it. Takes 10 seconds.
13. A Three.js Experiment Recreation
Aurelien pointed Fable 5 at one of Amin Ankward’s well-known Three.js creative experiments and asked it to recreate it.
The output was close enough to stop people mid-scroll.
This matters because creative coding in Three.js involves layered systems - geometry, shaders, animation loops, lighting - working together precisely.
Fable didn’t approximate it.
It rebuilt it.
14. A QDD Actuator - With Collision Validation Baked In
Jake Fitzgerald asked Fable 5 to design a quasi-direct-drive actuator - a specific mechanical component used in robotics for high-torque, low-backlash joints.
Not only did it output the design, but it also animated the gearbox and ran collision inspection as part of the validation loop.
30 minutes. 400,000 tokens.
This is engineering-grade output, not a toy demo.
15. Rigging and Animation Without Touching Blender
A 3D creator passed a .glb file generated with Hunyuan3D directly into Claude.
What came back included full rigging and animation - the character walks, flies, and plays piano.
No Blender. No manual bone setup. No hours of weight painting.
This one has real implications for solo 3D artists who’ve always been bottlenecked at the rigging stage.
Before you move on - slow down here.
What you just read isn’t a curated list of flukes.
These are 15 separate people, working independently, all hitting the same wall: the model did more than they expected.
That pattern is data.
Pay attention to what it means for the work you’re already doing.
The question isn't whether Mythos can do this.
It clearly can.
The question is: what are you still doing manually that you should have handed off last Tuesday?
If this is useful, share it with one person who needs it. Takes 10 seconds.
Fable 5 vs Opus 4.8 - Same Prompts
This is the only side-by-side test I found worth including.
Atomic.chat gave both models three identical prompts: a chaotic double pendulum, a Galton board, and water in a spinning drum (WCSPH).
All self-contained HTML5 physics simulations, no libraries allowed.
Here’s what the test actually showed:
Fable 5: $3.35 / 68,700 tokens / 14 minutes 47 seconds
Opus 4.8: $0.93 / 38,900 tokens / 8 minutes 10 seconds
Opus was faster and cheaper.
But on the water simulation - the hardest of the three - Fable produced a significantly more stable, continuous body of water.
Opus left gaps near the walls, scattered particles, and struggled to keep the fluid stable.
The tradeoff is real: Fable costs more and takes longer.
But on problems that require physical coherence over time, it holds together better.
This is the honest version of the model comparison.
Use Opus for speed tasks and iteration.
Switch to Fable when the output needs to hold together under pressure - physics, logic, long builds.
That's it.
If this is useful, share it with one person who needs it. Takes 10 seconds and costs nothing.
Before this issue, you'd heard Mythos was impressive.
After this issue, you know specifically what it does, what it costs, where it beats the competition, and what 15 real people built with it in 48 hours.
That's a different kind of knowing.
In 60 seconds:
→ Fable 5 built a working V8 CAD model in under 10 minutes
→ It rigged and animated a 3D character without Blender
→ It produced full game clones - Minecraft, GTA-style, Mario - in single sessions
→ It designed engineering-grade hardware (robot, actuator) with validation loops
→ Fable 5 beats Opus 4.8 on physics quality - but costs more and runs slower
Save this. Screenshot it. Come back to it.
Your gift - as promised:
A swipe file of all 15 Mythos use cases with direct tweet links, organized by category (engineering, game dev, creative coding, visual experiments) - ready to bookmark and return to.
Use it as a reference the next time someone asks you, “But what can it actually do?”
Here are a few issues that you might have missed (go check them out):
Clone Any Faceless YouTube Channel with Claude (Step-by-Step)
How to fix your Obsidian graveyard with Claude under 20 mins
I Gave Claude Fable 5 a Month-Long Project - Here is what happened
We tested it in public. Now go use it in private.
If this issue helped you, forward it to one person who needs it. It’s free, and it takes 10 seconds.
Sharing is always caring :)
And for shorter takes between issues, follow me on X → Hamza Khalid
PS: Which of these 15 use cases are you most tempted to try first? Hit reply - I read every response.
- Hamza 💙
Incredible showcase of what's possible with Claude Mythos.