A man who adamantly refuses to just go away. Well, actually he really has little say in the matter. The only character to appear in the whole Dune series by Frank Herbert (as well as the new Dune: House Atreides and Dune: House Harkonnen). Ironic, because it seems he dies at least once in every book. Serves the Atreides family semi-faithfully for several thousand years, consecutively and sometimes concurrently. He's a real tool. While the Dune universe slides perpetually into sexual perversion, Duncan Idaho stays pretty much the same.

In the David Lynch movie that only I seem to enjoy, Mr. Idaho is played by character actor Richard Jordan. Although he does not fit the profile 100%, he dies suitably dramatic.