I'm a Bionicle centrist, but from what's here I suppose it's obvious why this MOC appeals. I've never seen a geode done in LEGO form before, and barring the grey click-joints around the outside it looks real, too! Oh, and surrounding it with a giant rocky monster body is cool too.
WOW! This is amazing. The two faces are very well done, especially the craggy teeth. I also like the detail in the stomach when the front is removed. It looks like a natuarally-occuring phenomenon. Very well done.