Not The Mask in completion but rather the object itself -- or a reasonably facsimile. Trained on images of The Mask in prop form at some angles, including 3D models and variants based on the cartoon. In addition there is some training based on images of a fringe concept where the Mask is fused to skin but still wooden in some way.

Trigger words are "wooden mask" for the prop Mask, be sure to specify if it's a green mask or a brown mask.

On the same note, for partially transformed faces, the trigger word is "wooden face." You may or may not get interesting results having both trigger words at once. Or not. Try also prompts like "wooden lips" if you want The Mask's texture to influence your subject's face even further.