POMEZIA, Italy (Reuters) - Comic Beppe Grillo calls four-time Italian Prime Minister Silvio Berlusconi a "dwarf zombie", outgoing premier Mario Monti "rigor Montis" and Italy's political class "the walking dead". Grillo, founder of a movement that will rival even the biggest parties at elections next month, hopes to wipe out the old guard: "We will bring some exorcists to parliament," he said in an interview after a rain-drenched rally south of Rome. The 64-year-old Grillo is quick with wisecracks but the his 5-Star Movement is no joke. ...