Reb Aryeh Leib, the Shpoler Zeide

When Boruch hosts the Holy Baal Shem Tov, he sees a wondrous sight- the Maharal of Prague visits the Baal Shem Tov during Tikkun Chatzos and tells the Baal Shem Tov to inform his host that he will expect a son who will have the Maharal's neshomo. This boy grew up to become the famous "Shpoler Zeide".