At the End Times a man within a turban will herald the appearance of Hazrat Mahdi (as)

There will be a turban on his head; a man will appear from inside this turban, point to Mahdi (as) and shout aloud: “That is Hazrat Mahdi (as), Allah’s Caliphate! Obey him!” (Al-Barzanji, Al-Isha'ah li-ashrat al-sa'ah, p.164-165)

He [Hazrat Mahdi (as)]will sow a dry cane in a dry place, it will immediately grow green and leaf.