Silent Partner

"Groucho: Who is he?

Chico: Atsa my partner, but he no speak.

Groucho: Oh, that's your silent partner."

- The Cocoanuts

When He Who Must Not Be Heard is paired up with, and constantly seen with, another character who does all the talking.

If the Silent Partner is The Unintelligible, it may be the case that only his talkative partner can understand him. In Video Games, Heroic Mime protagonists commonly play this role.

Anime and Manga

 * Kabaji from The Prince of Tennis, who functions basically as Atobe's sounding board and is almost never heard saying anything other than "Usu" (meaning "Yes", in reply to whatever Atobe says).
 * Enryu from the Filler Arc of Bleach. Kenryu generally does all the talking for both of them.

Film

 * The View Askew Niverse: Silent Bob, of Jay and Silent Bob. He does have a few lines in each movie, though, usually centered around An Aesop.
 * Star Wars:
 * R2-D2, whose talking partner is C-3P0
 * Chewbacca, whose talking partner is Han Solo.
 * Harpo Marx usually played Silent Partner to Chico Marx, making this Older Than Television.
 * Star, the little girl in Terminator Salvation, never makes a sound through the entire movie despite being in the thick of several battles.

Live Action TV

 * Newhart: Larry's brother Darryl and his other brother Darryl.
 * Lizzie Mcguire: Matt McGuire does all the talking for his best friend Lanny.
 * Battlestar Galactica Reimagined: The Colonial One never says anything despite having quite a lot of screen time. He would always appear as if he was about to say something, only to decide to the contrary.

Webcomics

 * Angie from PS 238 translates for Prospero, an alien who is also The Unintelligible. She can apparently understand him, though nobody knows how yet.

Western Animation

 * Subverted in Kim Possible with toy developer Nakasumi and his assistant Miss Kyoko. It is later revealed that he can speak English quite well, but "enjoys whispering to Miss Kyoko."
 * Transformers Animated:
 * Of the three Dinobots, only Grimlock talks. Snarl and Swoop just make dino sounds in their beast modes. However, the writers have stated this is just because of limitations in the number of Voice Actors they can have in each episode.
 * The Mayor of Detroit and his aide. Opposite of what you'd expect, it's the Mayor that's the silent partner, and the aide who does all the talking for him.
 * There's also Perceptor and Wheeljack. Perceptor, despite his Creepy Monotone voice, is the only one of them to talk on screen.
 * Wallace and Gromit: Gromit plays silent partner to Wallace in show and films.
 * Phineas and Ferb where Ferb usually talks at least Once an Episode, but often only one or two lines. The rest of the time Phineas does the talking while Ferb just makes motions or subtle facial expressions.
 * Zee, the animated blue bird mascot partner of Moose A. Moose on the Nick Jr. network (formerly Noggin.)
 * Men in Black: Agent C. He's an operative assigned to deep sea work for months, and his only companion is a silent alien. This leaves C a bit...unhinged.

Real Life

 * Teller of Penn and Teller. Teller's act was mute before he teamed up with Penn. Inverted in the Penn & Teller zombies in Las Vegas short film, which is not only played straight but narrated exclusively by Teller.