My idea is that of a character that reads on different layers. The initial impact, thanks to theatrical lighting would be the silhouette of a human skull which is achieved by the person in the costume controlling the abdomen of the spider. Secondly the viewer will notice the smiling and inviting, pure white mask that is in front of the spider and thirdly the face of the spider itself behind the mask. Here's a visual explanation:
Still lots to refine on the colour scheme, fabrics, details and shapes but I hope I'm hitting the mark with the idea. Feedback is welcome.