The good counterpart to the Treacherous Advisor and The Starscream.
The Sarcastic Devotee is a Sidekick who always sticks around The Hero, The Messiah, The Captain, or any other lead role, doubting his orders, making sarcastic, often insulting comments about his actions (if the lead's ego is not strong enough, this may have complications) but never, ever actually betraying or leaving him in need. Deadpan Snarker, The Lancer, and sometimes The Smart Guy commonly fit this description, and a Poisonous Friend may have been this at the beginning. The nastier types of Hypercompetent Sidekick are often this as well. A reluctant Noble Demon may have this type of relationship with its Kid with the Leash. Can also overlap with Lovable Traitor or with Sour Supporter.
According to the theory of Dramatica, two archetypal roles are "Sidekick" and "Skeptic". The Sidekick supports you no matter what, and conveys positive feedback (you can do this, everything's gonna be okay). Conversely, the Skeptic (who may still support you) conveys mostly negative feedback (this'll never work, you've screwed it all up, we're all gonna die). Sometimes this can batter down and demoralize the hero; at other times, it keeps him grounded, helps him remember the stakes, and even strengthens his resolve for the long journey ahead.*
He's also this as Jason in Battle of the Planets. Mark definitely deserves sarcasm. Sometimes one wonders about the devotion.
Shinichirou Tamaki, one of Lelouch's lieutenants in the first season of Code Geass, who is nonetheless one of his most useless servants.◊ A more benevolent variation is C.C., who often doubts or mocks Lelouch and his plans, but always goes along with them anyway.
Shirin Bakhtiar, Princess Marina Ismail's advisor in Gundam 00. Although we never really saw enough of that pair to see what her real deal was, some viewers got the impression that she was stringing Marina along for her own purposes. Plus, she leaves in episode 25 (leaving Marina looking rather upset) but not before the Celestial Being incident is resolved and Azadistan is apparently on its way to solar age.
In Naruto, Sasuke fits but subverts it by actually leaving when the lead starts doing things right. Shikamaru fits even better but also subverts it by taking the role of leader himself around the same time.
Hyuuga and Wakabayashi sometimes act like this in Captain Tsubasa. Hyuuga even more so, as Wakabayashi lays down the snark a little when he grows up.
Manjoume Jun in Yu-Gi-Oh! GX insults Judai's stupidity all the time, but follows Judai to other dimensions and listens to him.
Atsuyu from The Twelve Kingdoms is the governor of En's biggest and richest province, and is rather cynical in regards to the new king Shoryuu. Horribly subverted when we learn that he's not a devotee, but a Smug Snake who wants to depose Shoryuu and become king.
Hawkeye of The Avengers embodies this trope so thoroughly, he's almost a better example of The Starscream. For years, he served under the leadership of Captain America and disputed every judgment call wing-head made; no matter how trivial, and never failed to punctuate his complains by claiming that he would make a much better leader. Even after Hawkeye got to lead his own team of Avengers, these arguments still cropped up every time he had to step back into a supporting role.
Batman's trusted butler (and surrogate father) Alfred is perhaps one of the most infamous of such characters.
Strongbow in ElfQuest. Spends a lot of time questioning Cutter's authority as chief, challenges him for leadership and loses, and later even walks out on him for a while. But when he's needed in a crisis...
In Ultimate Marvel, Tony Stark/Iron Man's butler, Jarvis. Until he, y'know, died.
Similarly, evil Mojo's butler and right-hand man, Major Domo, often comments on his very dangerous boss' craziness and round physique.
Captain Haddock often makes sarcastic remarks about Tintin's goody twoshoesness (and the trouble it sometimes gets them into), but will never abandon him.
In X-Men, Wolverine serves this role towards Cyclops. For a while in Wolverine's own book, Jubilee was his very own Sarcastic Devotee.
A good part of Cube is spent establishing Worth as a villainous character - and he is indeed eventually revealed to have some relation to their predicament - but in the end, he proves to be more heroic than de facto The Captain Quentin.
Sir Robin's faithful minstrels in Monty Python and the Holy Grail. "Bravely taking to his feet - He beat a very brave retreat, - Bravest of the brave, Sir Robin!"
Grantaire of Les Misérables is about as cynical as they come, yet follows Enjolras to revolution despite his disparaging remarks.
Savitri in The Last Colony / Zoë's Tale is so snarkily devoted she changes planets for her boss.
Ron Weasley in Harry Potter. He's among the most loyal characters in the entire series, but it takes very little for him to complain or snark about whatever they're doing.
Captain Hastings, Hercule Poirot's early Watson. Once Poirot failed to solve a mystery involving a box of chocolates. After that affair, Poirot tells Hastings that if he ever acts too conceited, he should use the words "chocolate box" to bring him down a peg. Poirot isn't amused when Hastings uses the code words a minute and a quarter later.
A truly odd example from the Artemis Fowl series. Opal Kobai can apparently mind control the doctor in The Time Paradox, but while it does make him follow her orders, he snarks and complains the whole time.
Agent/Colonel John Casey from Chuck does this exceedingly well. Actually it seems that Adam Baldwin plays this character type well, see: Cobb, Jayne.
Mr. Spock is very, very much loyal to Captain Kirk. But he doesn't hesitate to point the more "questionable" aspects of Kirk's plans (ala Zoe from Firefly). Sometimes, he does this with a well placed Stealth Insult.
Bones McCoy, who as Captain Kirk's chief medical officer and close friend is basically the only one on the ship with the license—and the chutzpah—to question Kirk's judgment openly. Spock is more polite and guarded.
Geoffrey Butler, the butler in The Fresh Prince of Bel-Air, and Florence, the maid on the The Jeffersons. Both stick with their employers despite hating them and having other options. (Ok, so Geoffrey leaves once, but it was just to make a point.)
Florence left once too but her spinoff show was cancelled I guess she decided to come back.
Although she and George don't get along she and Louise are close. Deep down she and George also like each other but never admit it.
Jayne Cobb from Firefly does this a lot, including plays to take over the ship. This one's subverted in the episode "Ariel," however, when he turns Simon and River, his two least favorite people on the crew, in to the Alliance for the reward money during the hospital heist on the eponymous planet, but ends up getting arrested himself right along with them and has to bust them both out again. Jayne is almost Thrown Out The Airlock by Mal when he finds out about what he did ("You turn on ANY of my crew, you turn on ME!").
Really, pretty much anyone who sticks around on Serenity becomes one sooner or later because, let's face it, Mal has it coming. Both the devotion and the sarcasm.
In fact, all of them do it except maybe Kaylee who is too sweet and River, who is River. Zoe is the best example because of the amount of devotion she has and her deadpan delivery.
Benson, the Tates' butler on Soap, who only sticks around to take care of Jessica Tate.
And then, Benson keeps doing it when he goes to work for the governor in Benson.
And so does Maxwell's butler in The Nanny. I think I see a trend...
A few of the Doctor's companions will occasionally point out the flaws in his plans, and in extreme cases, question his competence. This seems especially prevalent in the new series, as basically all the companions have done snarking on the Doctor's behalf.
Two words: Donna Noble, with her habit of calling the Doctor "Spaceman".
Amy Pond on the Doctor being a Time-Lord; "That's just what they're called, it doesn't mean he knows what he's doing."
Averted by Katarina in "The Dalek's Master Plan" and likely the reason why she was quickly bumped off. A Companion who views the Doctor as a god isn't any good for the series.
Toby Ziegler on The West Wing, whose snarking and complaining are actually things that President Bartlet highly value.
[Future!Dean has just suggested a suicide attack, and objected to Cas's description of it as "reckless".] Future!Cas: If you don't like "reckless", I could use "insouciant", maybe. Future!Dean: Are you coming? Future!Cas: Of course.
This is Avon from Blake's 7 to a T - even after Blake disappears.
Debatable. Avon shows some traits of this, but on numerous occasions he goes beyond sarcasm and into power games, trying to undermine the crew's support for Blake. He also takes the ship away to protect himself more than once, when Blake is counting on him to teleport them to safety.
He seems to be tied to this trope by a piece of elastic; the farther he stretches (taking the Liberator away) the harder he comes back (and ends up rescuing everybody). It depends how seriously you take his intentions — it is worth noting that when his actions did have bad consequences for the others (and Blake) he actually felt guilt about them.
Dark Oracle: Simone is one of these to Vern, whom she may or may not have a crush on. No matter how moronic Vern's plans are, Simone sticks by him, mocking him the entire time. She finally leaves when he goes completely overboard and orders her to get lost.
Theatre
Dick the Butcher from Henry VI Part 2: During the speech when rebel leader Jack Cade claims he's rightful heir to the throne, Dick gives scathing asides mocking the veracity of these claims. However, after the rebel uprising, he's singled out by Cade for being the man with the highest hit count. The Butcher indeed.
Although less so if the player is doing well. In that case he saves his sarcasm for Slippy.
A villainous example in The Witcher: Azar Javed's Dragon, The Professor, criticizes Azar in messages and openly berates him in combat, but is always there on command and follows orders, likening himself to a summoned genie. He stops short of being The Starscream in that he never considers betraying Azar, even when he's up against a wall with his life at stake.
Archer from Fate/stay night, though he subverts it in Unlimited Blade Works. And on the villain-ish side, Assassin plays this role towards his master, Caster.
Fire Emblem The Sacred Stones, has Rennac, a mercenary employed by L'Arachel, the Princess of Rausten. It's pointed out in the ending that he doesn't actually try very hard to escape her service despite his comments towards her actions.
In Mass Effect, the ship's pilot, Joker, resembles this. There's no doubt he's snarky, but he's got the commander's back.
"Oh, another dangerous alien aboard, Commander. Thanks. Why can't you collect coins or commemorative plates or something?"
Etna from Disgaea is the only one of the late king's vassals willing to serve Laharl, and she's quite sarcastic to him, since he's a Royal Brat. Even though she uses him as bait to stop Maderas, she genuinely feels guilty about doing so, since she promised the king, the only person to ever show her kindness, that she'd protect his son.
In the sequel, she leaves him after a fight, but she returns to him after Flonne gets them to make up and apologize.
Pink in Dark Hero Days constantly makes thinly veiled insults towards Axel, but he's completely oblivious to them. Fenrich in Disgaea 4: A Promise Unforgotten also makes insulting remarks towards his master Valvatorez, but he doesn't seem to care, either.
In Persona 3, Shinjiro Aragaki is brusque and standoffish with the male protagonist, telling him not to try to tell him how to fight and snarking at him in combat when, for example, the protagonist heals him ("Tch. I don't need your help.") or gives him an order ("Who does he think he is?"). It's mostly a front (and he's noticeably less belligerent toward the female protagonist).
Tails has mild shades of this in recent Sonic the Hedgehog games, he makes the odd bewildered or exasperated remark towards Sonic's wackiness but otherwise is a devoted friend and right hand man.
Lydia is one of the strongest followers in Skyrim, but sarcastically says "I am sworn to carry your burdens" whenever you use her as a pack mule.
Everyone in Something Positive is like this: they'll snark each other to shreds, but are fiercely loyal to each other.
Nodwick's title character, as well as the henchmen in general. Although nominally bound to his party due to his draconian labor union laws, Nodwick does actually care for them (mostly, anyway).
Piffany, at least. If Artax and Yeagar were to let up on the abuse he probably wouldn't cry I want my jerks back anytime soon.
Just about every sidekick in Girl Genius strays into Sarcastic Devotee territory now and then for comic relief. But Moloch (a soldier and mechanic who's bitterly aware of the life expectancy of sidekicks in this world) and Violetta (a bodyguard who's convinced that her charge is suicidally stupid) are pretty much permanently unimpressed with what the main protagonists are doing.
Gil Wulfenbach can be like this at times (especially in regards to his father's employee relations methods compared to his own), and he's one of the madmen people sidekick at.
Rattrap in Beast Wars is very critical of Optimus Primal, questioning Primal's leadership skills and loyalty radar (particularly in relation to Dinobot and Blackarachnia) at various times. However, he would never in a million years betray Optimus or try to usurp command from him. His living quarters are fair game, though.
Of course, since he was elected as Optimus' second should something happen, this makes his loyalty to Optimus as much self-preservation as anything.
Kiff of Futurama sticks behind Zapp Brannigan no matter what (probably because it's his place in the military), but makes it painfully obvious that he hates Brannigan for it. Oddly enough, Zapp is never fazed by Kiff's commentaries.
Being a moron, it's likely that Zapp isn't aware that he's being mocked.
That and he just thinks Kiff is a massive coward -which, to be fair, isn't far off the mark.
It seems to go beyond his line of work, even when they were both fired from their ranks (almost entirely because of Zapp) Kif still acted like his usual submissive (but sarcastic) self towards Zapp despite no longer having any power around him.
Sokka is arguably the better example because it's actually part of his Character Development. Throughout the first 2 seasons, he constantly questions both Aang's and Katara's judgements, making sarcastic quips concerning their Chronic Hero Syndrome and their reliance on Bending and anything mystical. By the third season he almost completely grows out of this, coming to fully trust in Aang.
