Procedural generation isn’t just for static things; there’s a related field of procedural animation that generates movement for animated characters and things. In this case, that thing is spiders. 

This video showcases the research of Llyr ap Cenydd and Bill Teahan, for their paper “The dynamic animation of ambulatory Arthropods”. Llyr has a blog where he discusses the VR projects he’s working on, which naturally include some discussions of procedural animation.