I didn't know about the cone head glitch, do we have any idea what triggers it? From looking around random YouTube videos, just about all of them say it happened during combat, but no one seems to have a video of the glitch actually happening or having something more concrete about how to do it. I'd definitely look into it if I knew how to do it, but I've never had that happen to me before.
Also, I lol'd at this video.
Also, I lol'd at this video.