Which figures do you recall have some really cool sculpting that is hidden/obscured

I am tying to think of all these figures that have either easter eggs or really cool sculpting that is not seen nor needed on a toy. Like 10th Anniversary Primal who has a ribcage behind his gorilla chest, or Titans Return Hot Rod who has all sorts of sculpting showing layers below his chest and even universe Powerglide's heart.
Which kinds of details like that come to mind for you?
Which kinds of details like that come to mind for you?