In brief return to his past comedy career, Ukrainian president jokes about Russia's military performance during appearance on the talk show host's new series

Jewish TV personality provided opening introductions for CBS' 'The Late Show' from 1995 until last episode in 2015; community rabbi describes him as 'a true mensch'

The mess of platinum hair has become a symbol in an era where celebrity and politics combine, symbolizing his chaotic and gaffe-prone style that charms supporters, appalls critics