This isn't a new idea on the site, but it's easily my favorite custom I've made because of the long story.
It started when I saw benstoys custom Two-Face made w/ Captain America's head, I had that head, so I made it. After about a year of retooling the head, I got a thug body and went through the long process of giving him new hands (not knowing of the boiling method yet).
All sculpting done with a package knife, for I didn't own a dremel. Then the new method of making Two-Face with the amazing new head came out, so I shelled out the cash for a dremel, made this head, and gave a final repaint of the suit.
Scarecrow's hands and 4" Indiana Jones gun repainted silver w/ black handle. Scarecrow's finger goes right into the hole. Perfect fit. I'd recomend it.
Only problem is now my old Harvey (Unburnt) isn't the same because he has the old head, so he looks nothing like this. If only they released that 5" Harvey they made a prototype for, I'd be golden.