Tycho Nestoris is a character in the fourth season. He is played by Mark Gatiss.
Biography
Tycho Nestoris is a representative of the Iron Bank of Braavos who has been sent to Westeros to negotiate payment of the Iron Throne's massive and long overdue debts, which have been accruing since the reign of King Robert Baratheon.
Season 4
In the books
In the A Song of Ice and Fire novels, Tycho Nestoris is described as a tall, gaunt stick of a man with long legs. He has a gaunt face with a thin rope of a beard growing from his chin which hangs down to his waist.