Obtained by merging 

https://huggingface.co/waifu-diffusion/wd-1-5-beta3

with 

https://huggingface.co/stabilityai/stable-diffusion-2-1-unclip/tree/main



For how to use this in ComfyUI and for some information on what unCLIP is see: https://comfyanonymous.github.io/ComfyUI_examples/unclip/