The annual Greenwich Village Halloween Parade on Sixth Ave. was ghoulishly good fun for one and all. As expected, there were some Donald Trumps and Hillary Clintons and at least one whiskered Pizza Rat duo toting a big tasty pepperoni slice between them. There was a Ms. Argentina, too, who seemed to have something gnawing at her — namely, herself! And you really had to give a hand to one marcher — who had an extra one on her shoulder. One float honored those lost in the past year, from Omar Sharif to Cecil the lion.