Neferet the Green
Neferet the Green, @, is the Wizard quest leader. She is made slightly more dangerous than most quest leaders by the fact that she can cast spells. As she has quite a high base level, some of those spells can be quite nasty. Of course, if you are attacking your quest leader, you've probably already lost your game.
Neferet the Green replaced the Wizard of Balance as Wizard Quest Leader in NetHack 3.4.0, perhaps because Wizards, who were always Neutral up to and including NetHack 3.2.3, can now be Neutral or Chaotic. Your quest leader's alignment is adjusted to match your starting alignment, and it doesn't make sense for a Wizard of Balance to be chaotic.
Neferet the Green may be a reference to Nefertiti, an Egyptian queen of the 18th dynasty, or to Nofret (also sometimes called Neferet or Nefert), an Egyptian princess from the 4th dynasty. 'Nfr-t' being a transliteration of the hieroglyphs meaning "beautiful woman". Efforts to find references to "Neferet the Green" outside of a NetHack context have so far failed. However, given that the Wizard role uses a Pantheon of Egyptian gods, a reference to Ancient Egypt seems likely.
Neferet the Green holds office in her hidden tower, only
reachable by magical means, where she teaches her apprentices
the enigmatic skills of occultism. Despite her many years, she
continues to investigate new spells, especially those involving
translocation. It is further rumored that when she was an
apprentice herself, she accidentally turned her skin green, and
has kept it that way ever since.