President Obama and First Lady Michelle Obama will host their final Halloween at the White House on Monday, inviting local children and military families over for candy and festivities.Revelers always bring their A-game to the White House trick-or-treat event, with a baby Pope, young Jedi and a Wizard of Oz family among some of the more memorable costumes. Since Monday’s event will be the last of the Obama presidency, attendees will surely go all out.