You will need
https://huggingface.co/comfyanonymous/cosmos_1.0_text_encoder_and_VAE_ComfyUI/tree/main
oldt5_xxl_fp8_e4m3fn_scaled.safetensors -> ComfyUI/models/text_encoders
cosmos_cv8x8x8_1.0.safetensors -> ComfyUI/models/vae
Note: oldt5_xxl is not the same as the t5xxl used in flux and other models. oldt5_xxl is t5xxl 1.0 while the one used in flux and others is t5xxl 1.1
https://huggingface.co/mcmonkey/cosmos-1.0/tree/main
Goes in: ComfyUI/models/diffusion_models
Note: "Text to World" means Text to video and "Video to World" means image/video to video.
If you want the original diffusion models in .pt format the official links are:
https://huggingface.co/nvidia/Cosmos-1.0-Diffusion-7B-Text2World
https://huggingface.co/nvidia/Cosmos-1.0-Diffusion-14B-Text2World
https://huggingface.co/nvidia/Cosmos-1.0-Diffusion-7B-Video2World
https://huggingface.co/nvidia/Cosmos-1.0-Diffusion-14B-Video2World