Always liked this style of zombie. Already some great loras of the main characters, so now they have something to fight. :)
Main Triggers:
hsotd_zombies, horror \(theme\), zombie, grey skin, empty eyes
stuff like blood, gore, destruction, chaos will add to the overall piece.
If making a text to image I suggest creating it with normal characters than inpainting over the ones you want to zombify. Also, if upscaling an image, I suggest doing it at 0.1 or the checkpoint might mix up the characters.. then inpainting in the details.
While it was trained on a number of images with the school uniforms, I don;t think its strong enough to overmask the checkpoints 'school uniform' so I'd suggest using one of the HSotD character loras to get those accurate.