Hugging Face ‘numbat’ repo claims leaked Anthropic model, but the weights look synthetic

A 7.72 TB upload billed as a Mythos-class checkpoint appears to contain tensors generated from their own names A Hugging Face repository called “numbat” claims to hold a mid-pretraining checkpoint from Anthropic’s upcoming Mythos-class training run. If real, it would be one of the most significant AI leaks on record. Community auditors say it probably isn’t real. Their analysis suggests at least part of the upload was manufactured from scratch rather than lifted from an Anthropic data center. What the numbat repo claims to be The repository sits under the username burner22, an account created on October 16, 2026. The upload followed a week later, on October 23, 2026. The model described in the repo is enormous. It reportedly packs approximately 14 trillion parameters spread across 114 layers. The claimed architecture also mixes a hybrid GDN/MLA design with 1,224 Mixture of Experts (MoE) components. MoE is a setup where the model is carved into many specialist sub-networks, and only a handful switch on for any given input. The files themselves total around 7.72 TB across 772 safetensors shards. Safetensors is a common file format for storing model weights, chosen partly because it i...