Wizard Sinterklaas is a wizard and librarian in the Wizards' Tower. He is involved in A Towering Feast. Players need to speak to him in order to start the event. He is somewhat forgetful and isn't very sure about what he is supposed to be doing, something that is often criticised by the guests from the Magic Guild.
He is a reference to the Dutch and Belgian holiday named Sinterklaas, which is one of the sources of Santa Claus. Despite being similar to Santa Claus, Sinterklaas is celebrated on the evening of 5 (6 December in Belgium), and is unrelated to Christmas (except for the fact that Santa is derived from Sinterklaas). The reference is further supported by the fact that the wizard wears a red hat, similar to Sinterklaas's red mitre.
His examine is a reference to Magic, a song by Pilot.
He claims to be librarian on the 7th floor of the tower, and that the tower is bigger from the inside for wizards than it is outside. This is a reference to the TARDIS, from the television series "Doctor Who". It could also possibly a reference to the Scale Theory.