Handy Helper

Alice has a handicap or deformity. And we're not talking inspirationally or awesomely disabled here. We're not playing it for quirkiness or to make her stand out. This disability is a genuine handicap which makes Alice's life harder, and perhaps even affects her self-image and sense of worth. For purposes of illustration, let's say Alice has no hands.

Bob loves Alice, and is dismayed by her sadness over her handicap. So Bob takes Alice's face tenderly in his hands and tenderly tells her "Do not worry, I will be your hands."

And Bob makes good on his promise. Bob feeds Alice, he applies her make-up, he writes her letters, dresses her. Hell, he becomes so familiar with Alice's quirks and behavior that he can even anticipate her, cupping her mouth when she yawns, holding a finger to her nose when she's about to sneeze, scratching her where she itches before she even tells him.

This is trope is a character compensating for another character's disability or deformity by basically becoming the appendage the other person is lacking. This altruistic attitude is usually attributed to, at least, a bond of friendship, and often is borne out of genuine love, be it brotherly, parent-child or romantic.

Compare The Caretaker

Example:

Anime and Manga

In One Piece, Chopper, the medic, is unable to move very much after after using Monster Point so Robin helps him with medical duties, by moving him around.
Used and brought to a mentally scarring twist ending in Franken Fran.
In Fullmetal Alchemist, Colonel Mustang fights Father while blind, with Lieutenant Hawkeye serving as his eyes.
At the end of El Hazard, the hero and the chick cooperate like this - he wields the sword while she helps him with her ability to see through illusions of the Big Bad.
In a chapter of Black Jack, an aspiring sushi chef is accidentally hit by a truck driver and loses his arms. To make amends, the driver offers to help the chef by serving as his hands. However, in a cruel twist of fate, the truck driver is himself killed in a traffic accident. Black Jack ends up grafting his arms onto the sushi chef.

Film

In Santa Sangre, protagonist Fenix quite literally is his mother Concha's arms and hands, as he stands behind her and uses his hands as her own, to the point that they almost move without his conscious thought. Which is actually true, since when Concha commands her to kill The Virgin, Fenix literally cannot stop his hands from doing so.
In Mad Max Beyond Thunderdome, Master is an intelligent-yet-physically-weak midget. The strong-yet-dim Blaster (he has Down Syndrome) serves as Master's arms and legs.
In the Richard Pryor/Gene Wilder flick See No Evil hear No Evil, they play friends who are blind and deaf, respectively, who compensate for each other's handicaps.
In Once Upon a Time In Mexico, Agent Sands is blinded and has to rely on a street kid he met earlier to guide him around.
In the The Bone Collector Amelia takes over the job of of Rhymes and kills Thompson
In The Incredible Mr. Limpet, the title character loses his glasses, so his crab friend Crusty becomes his eyes.
In Ratatouille, Linguini is a bad cook (not sure if he's a Lethal Chef, but he's close). Remy is a good one, but he also happens to be a rat. They discover that if Remy hides in Linguini's hat, Remy can smell the ingredients and direct Linguini to choose the right ones by pulling his hair.
In Blindness a woman who is immune to the virus causing blindness helps guide seven blind people.
Anatha is arguably a little bit like this for Bethany in Soul Surfer in some ways. On her facebook site Bethany as much as called her that in Real Life.
- Arguably a subversion. Bethany manages to get along reasonably well. What she does get from friends and family is encouragement.

Literature

In The Sharing Knife series, Dag is one-handed. Normally this isn't a problem for him, but when he breaks his other arm, his then-fiancée Fawn ends up acting as his hands.
In the Little House On the Prairie series, Mary is stricken blind and her sister Laura becomes her eyes by describing everything she sees for Mary's benefit whenever she asks.
Gathering Blue provides a proposed mutual example. Kira's father turns out to be alive despite his being Left for Dead before Kira was born and now lives in a village where people with disabilities all live this way. He is blind and offers Kira the chance of coming with him to his village, with Kira as his eyes and him as her legs (Kira has a deformed leg).
In The Book of Exodus, Aaron serves as his brother Moses's speaker, since Moses has a speech disability.
Magpie and Dog in Fox by Margaret Wild. Magpie's wing was injured in a forest fire, and Dog has only one eye, so Magpie rides around on Dog's back being his binocular vision, and when he runs it's almost as good as flying.
Ben-Hur has a mutual example. When Simonides and Malluch meet in the dungeons and are both released, Simonides acts as Malluch's tongue and Malluch acts as Simonides' legs.
- In the film version (not sure if it's in the book) Simonides says "together we make a considerable man".
Freakthe Mighty (and of course the movie adaptation, The Mighty) is a mutual example of this. Freak is brilliant and outspoken but frail, while Max is big and strong but none too bright; together they can face down just about anybody.
At the end of the Mage Storms trilogy, Karal's eyesight is burned out. He can only see through his mind link with Altra. When Natoli writes to ask him to return to Valdemar, she says "I can be your eyes too" (not literally, as she doesn't have any Psychic Powers).
Invoked in Fate/Zero; when Kayneth becomes crippled as a result of getting shot by Kiritsugu's Origin Bullet, Sola-ui offers to become Lancer's new master, whether forcefully or otherwise.

Live Action TV

One episode of MacGyver has MacGyver and his boss, Peter, working together. Peter has been temporarily blinded and MacGyver can't use his hands. Together... they can operate a golf cart!
Invoked in an episode of The Mentalist where Jane gets a millionaire to let him drive his car while blindfolded - Jane steers by having the person's hand on his shoulder, responding to his tension as Jane drives.
In Star Trek: The Next Generation Riva a diplomat is deaf from a hereditary genetic deficiency, but has his "chorus", an entourage of three people in telepathic communication with Riva and able to enunciate his thoughts. This trope is repeated in the same episode when Riva's "chorus" is killed and Data must read his sign language and translate for him This happens in another episode of Next Gen where LaForge and a Romulan lose the use of some of their senses due to interference from the planet Galorndon Core, and compensate for each other's lost senses
Red Dwarf:
- Spoofed in season I when, after being brought back to life as an hologram Rimmer asks Lister to be his hands. Lister refuses on the grounds he knows the type of things Rimmer liked to touch.
- In a season VII episode Lister has lost an arm, so Kryten does everything for him, including things he could still do, like wiping his mouth with a napkin.
In Firefly Simon Tam is River's Amygdala built for two.
Sue Thomas' dog in Sue Thomas: F.B.Eye

Tabletop Games

Subverted in D&D - The naga are a race of snake-headed humans and most of them cope just fine, either through dextrous mouths or magic. However, they do notice the trope and consider it a proof that they are a superior race - after all, they are best suited for thinking, while lesser creatures serve as their limbs - so this must be the intended natural order.

Theatre

In King Lear, Glouscester's faithful son Edgar (under the guise of Poor Tom) leads his father around after his eyes are plucked out on Edmund's orders.

Toys

Bionicle: in the Mata Nui Online Game, Takua becomes Pohatu's eyes when the latter was blinded by a Nui-Jaga.

Visual Novels

Rin from Katawa Shoujo has no arms, and Emi helps her with things she cannot do (although Rin is quite able on her own). Another character who does this, Misha serves as a Translator Buddy to deaf-mute Shizune.

Webcomics

In Wurr, the resident Ill Guy Sinjal is carried around on his packmates' backs.

Western Animation

One of the The Land Before Time sequels had villains Dil and Ichy, a near-blind crocodile and a bird, respectively. Ichy would act as Dil's eyes.
The Classic Disney Short Morris the Midget Moose is about a tiny moose with normal-sized anlters. He meets up with a normal-sized moose with tiny antlers, and the two combined themselves to make one complete moose.
An episode of The Smurfs had Brainy lose his glasses, so he is forced to rely on Clumsy, whom he had earlier derided as being useless.

Real Life/Urban Legend

A cop sees a car driving erratically, pulls it over on suspicion of drunk driving. Turns out the driver is blind. He's driving because his passenger is drunk (so he's acting as Designated Driver), but the drunk passenger is giving the blind man driving directions because the man is blind.