Physically, Madame le Trivia is a sack of flour, but it's been established that inside of the flour is a robot known as MT-42, which is a slightly corrupted designated knowledge-drone. He always wears a hat, whether it's his usual knowledge-party hat, a top hat, or Pinkie Pie in a saloon dress.
He's a lurker on the brony mumble, and has a bizarre fascination with the phenomenon known as Doctum Face.
More recently, Madame le Trivia has begun posting as Audrey II from Little Shop of Horrors for some bizarre reason. Madame le Trivia appears on /oat/ and /chat/ most of the time.