I might as well show some of my progress so far.
What I want to do for Waspinator is emulate the original toy, which had 2 heads, the normal head, and the Mutant head which we are all familiar with. So, I am shaving and moulding Tomahawk's normal head to look different, then shoving a magnet into his skull in order to attach a "mutant" mask. For the mask I am using a head from one of my S.H.Figuarts Kamen Rider figures (rider fans will know which one by the photo
)
Here is what I have so far, All pieces are unpainted and completely not finished, so right now it doesn't look at all like our favorite Wasp. I still need to do a lot of shaping, and add Mandibles.
I have the magnets installed, and I am very happy with the result. The middle piece snaps on perfectly.