You asked for it, here it is. My how-to showing the technique I used to affix Fangz and Waspix / Scorpio heads to my Boravus 3.0 and Lennick 3.0 MOCs. Savage Planet villain heads as Hero Factory hero helmets may look pretty good, but the technique itself ain't good at all! Works for display, but not play. Good enough for photos, overview videos and basic stop motions, but not for regular use.
Now ya know!