The Greek Chorus has four people in it. All of them have red cloaks. They all have white masks. The first person from the left has a surprised face, the second has an angry face, the third has a happy face, and the last has a sad face.
They appear during the title card and say that they will be narrating the episode. They give commentary throughout the episode.
The angry person by far changes his respective facial emotion the most, since he can move his mouth relatively better than the other three people. Most of the others simply keep their facial expressions exactly the same regardless of situation.
They are the first group of characters to narrate a title card while shown on screen