A post on r/ClaudeAI made a dramatic claim this morning. A Hugging Face account named burner22 had uploaded a file called numbat. The poster said it held Anthropic's next model, the one code-named Mythos.
The claim came with huge numbers. The file held 772 weight shards. Together they totaled 7.72 terabytes, enough for 14 trillion parameters.
The post spread fast. It pulled 198 comments on Reddit. A matching Hacker News thread added 30 points and 12 comments of its own.
Readers had a reason to wonder. Anthropic's Claude Code source code leaked back in March. That leak named numbat as a real internal codename.
Then a second poster tested the file directly. They read the shards with range requests. They checked the math against a known model, Qwen2.5-7B.
Two tests settled the question fast. One weight table matched another table's math, row for row. A setting called input_scale changed between parts that should share one value.
The verdict: the file is fake. Someone built real wrapping around invented weights. The word list and the embedding table came from a true model. The giant number inside came from a generator, rather than from training.
The fake still earned real traffic. It pulled 87 likes and 5,846 downloads on Hugging Face before anyone called it out.
The case shows how good a fake can look now. A faker can copy a real word list. It can hit a real size and dress up a hoax in sound math.
Readers tested the numbers themselves instead of trusting the headline. That instinct caught this fake inside hours.
Anthropic has stayed quiet in public about the file. The company's real Mythos model stays unreleased, confirmed only by that one line from March.