The Emcee is a special character featured only in City Folk. She announces Dr. Shrunk's or Frillard's show, featured at The Marquee at the City, after paying the Clerk 800 Bells and choosing an emotion to learn. The species of the Emcee is unknown, as she is always off-stage, announcing the show. Emcee's name is a pun on MC, or master of ceremonies. The Emcee is not a human because she speaks Animalese while the player speaks Bebebese. The Emcee is also a female due to her voice.
Warning: Theory starts here.
The Emcee is the Clerk
The Emcee may be the Clerk because she acts in the same way and is of the same gender. They also have identical voices.