[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/Sonic_Underground_7556.jpg]]
[[caption-width-right:320:Left to right: Sonia, Sonic and Manic.]]

Adapted from a French cartoon called ''Sonic le Rebelle'', '''''Sonic Underground''''' is the third ''Franchise/{{Sonic|TheHedgehog}}'' AnimatedAdaptation made. It was produced by Creator/DICEntertainment.

Sonic and his two siblings, Sonia and Manic, are left by Queen Aleena as {{Doorstop Bab|y}}ies to families, each of a different class. Eventually, they meet together when grown up, and guided by the Oracle of Delphius, they set out to thwart Robotnik, find their mother, and form the Council of Four.

Thanks to so many original characters and the omission of almost all the official characters existing at the time, despite there being potential room for them (Cyrus could easily have been Tails), and since many of the background characters were more alien than any Earth-based animal, many ''Sonic'' fans and even fans of the series debated whether it was really even intended to be a ''Sonic'' show, and that the characters of Sonic and Dr. Robotnik were just a hook for ''Sonic'' fans. Even the series plot is basically a ThisIsYourPremiseOnDrugs take of the Sonic vs. Robotnik story.

Regardless of the characters used, it was most likely the "hook" for the show that resulted in its thorough panning. This was that the ''real'' premise of the show was that Robotnik had banned all music, and our three protagonists were {{Musical Assassin}}s with ThePowerOfRock. Each episode's climax would inevitably be a song performed by the triplets, often with AnAesop based on the events of the episode.

Not to be confused with the [[WesternAnimation/SonicSatAM two]] [[WesternAnimation/AdventuresOfSonicTheHedgehog other]] {{western animat|ion}}ed series based on Sonic the Hedgehog, the {{Anime}} series ''Anime/SonicX,'' the {{OVA}} ''Anime/SonicTheHedgehogTheMovie,'' or the game that helped to [[CutShort kill it off]] that same year, ''VideoGame/SonicAdventure''.

Now on DisneyXD and {{Netflix}}.

After 10 years of being CutShort, it seemed that [[http://www.bumbleking.com/forum/viewtopic.php?f=4&t=6519&start=30 the story would conclude]] in the [[ArchieComicsSonicTheHedgehog Archie Sonic Comic's Sonic Universe]]. Sadly, it was delayed, and now [[https://twitter.com/IanFlynnBKC/status/510281489292877824 it's been officially cancelled]], though a summary of its events will appear in a collection of planned and scrapped stories.
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!!''Sonic Underground'' provides examples of:

* ActionGirl: Sonia.
* AnAesop: Almost every song in the show.
* TheAllegedCar: Sonic, Sonia, and Manic's RV van. The thing is pretty groady-looking on the outside and looks as though it could fall apart at any time. But it manages to lug around the hedgehogs and their stuff pretty well. One of the very few times it actually breaks down, it's because Sonic tried to cook a chili dog by leaving it on the RV's engine.
* AnimationBump: Occasionally, most prevalent in the opening.
* TheArtfulDodger: Manic.
* ArrangedMarriage: Sonia to Bartleby, and Queen Aleena to Robotnik in one episode.
* ActionHoggingOpening
* AutobotsRockOut
* BadassMustache: Dr. Robotnik.
* BeautyIsNeverTarnished: In "The Big Melt", despite being triplets, Sonia's bare feet are much daintier than Sonic and Manic's.
** Averted in "The Price of Freedom," where Sonia getting her hair and outfit completely wrecked kickstarts the plot.
* BigFancyHouse: Sonia used to live in one, and her friend Mindy does at the start of "The Price of Freedom."
* BlueBlood: The various aristocrats.
* BreadAndCircuses[=/=]AristocratsAreEvil: The series shows [[FridgeLogic how Robotnik can afford to stay in power]]. The upper-class aristocrats can either provide his funding, or lose their land and privileges, and risk being roboticized.
* BrokenAesop: The 21st episode involves a seller with one of the Queen's gems and willing to sell it at a high price. The trio doesn't have the money and Manic ruefully recommends '[[StickyFingers acquiring it.]]' Sonia and Sonic are disgusted with Manic's thieving skills and shoot it down, [[{{Hypocrite}} even though they have stolen things before]] and Manic has taken things that saved their lives. Later Sonic's ingenious way of getting Sleet and Dingo out of their ship is to flood it with gallons upon gallons of unpaid for olive oil.
* ButtMonkey: Dingo, and Robotnik at times.
* CanonForeigner: Besides most of the main characters, a notable example is Cyrus, a lion and member of the resistance movement.
* CanonImmigrant: Knuckles's grandfather, Athair, was a character from the Archie ''Sonic'' comics.
* CatchPhrase: Much of Sonic's catch phrases from ''Adventures'' and ''[=SatAM=]'' were carried over, along with a few new ones, such as "Bummer mejores!".
* CharacterDevelopment: Yes, there actually was some. In the beginning, Sonia was pretty whiny, prone to complaining whenever her appearance was tarnished. Later in the series, she becomes more of a leader figure, and is easily the most focused of the siblings.
* ChattyHairdresser: The Do-Bot, who turned out to be a spy for Robotnik.
* ColorCodedForYourConvenience: The lasers their instruments shot were color-coded.
* ChromaticArrangement
* CutShort: They made a vow their mother will be found... but she never was. The series ended early. [[http://www.bumbleking.com/forum/viewtopic.php?f=4&t=6519&start=30 Until now...]] [[DevelopmentHell perhaps?]]
* DeadpanSnarker: Sleet.
* DeusExMachina: Queen Aleena made sporadic appearances to save the hedgehogs at times.
* DisguisedInDrag: Sonic and Manic have no qualms with dressing up as ladies to fool Robotnik and his goons.
** Actually, they had SOME qualms about it in the episode where Sonia lost her memory, until they actually implemented the plan for the first time.
* DishingOutDirt: Manic, who can cause earthquakes.
* DisappearedDad: No mention has ever been made to Aleena's husband/the siblings' father. Not even in the Mirror Universe.
* DissonantSerenity: Early in the series, there was a strange problem with the animation where the characters would be smiling, even when talking about something depressing or when something bad was happening. This was fixed as the series went on.
* TheDogBitesBack: Happens ''twice'' within the same three-part episode. After Robotnik builds a Chaos Emerald-powered flying fortress, Sleet and Dingo grow concerned that they've [[YouHaveOutlivedYourUsefulness outlived their usefulness]], so they steal the Emerald and escape. Then Dingo, clearly tired of being slapped around by Sleet, steals the Emerald from ''him''.
* {{Dogfaces}}: Many of the extras look like extraterrestrial versions of Disney-style dognoses.
* DoorstopBaby: Sonic and Sonia; Manic was stolen from his.
* DumbMuscle: Dingo.
* EasyAmnesia: Sonia in "Who Do You Think You Are?"
* EightiesHair: Sonia and Manic.
* EpisodeTitleCard: With the group portrait above as a backdrop.
* EverythingsBetterWithSpinning: Sonia's Super Twirl.
* EvilDebtCollector: Sleet and Dingo are this to both the aristocrats and the people of Mobodoon.
* EvilOverlord: Robotnik, naturally, although there is a lot that separates him from the Robotnik of SATAM. SATAM Robotnik's end goal is to roboticize all sentient life in order to consolidate his control of the planet. Underground Robotnik also desires worldwide domination, but is willing to be more open to the various ways of achieving this, including shaking down the rich for resources and relying upon unroboticized help. Also, Underground Robotnik isn't keen on polluting environments unless it somehow serves his purposes, and leaves most people unroboticized, treating the procedure more as a punishment for crimes committed against his rule.
* ExpositoryThemeTune
* FailureIsTheOnlyOption/ CosmicPlaything: When Sleet and Dingo do their jobs of trying to capture Sonic, Sonia, and Manic, they fail. When the come up with plans that would mess up Robotnik... they still fail.
* FeudalFuture: Robotnik basically just extorts tribute from the aristocrats under threat of roboticization.
* ForgottenFallenFriend: The foster parents/educators of the hedgehogs were arrested and roboticized at the end of episode 1... and almost never thought or spoken of ever again in the show.
* FullyAbsorbedFinale: The series' story is finally getting a conclusion through the ''[[ComicBook/SonicTheHedgehog Archie Sonic the Hedgehog]]'' comics. Specifically, through ''Sonic Universe''.
* GenreSavvy: Sonic tends to be this and often realizes when things aren't normal and is suspicious of most things with good reason.
* GossipyHens: Sonia chatting with her hairdresser turned deadly when it was revealed she was a spy.
* GroupHug: Seen a lot.
* HalfwayPlotSwitch: Used, and nearly invoked, in "Wedding Bell Blues." Since Queen Aleena didn't show for her forced marriage to Robotnik, they'll instead crown Sonia queen in her stead.
* HarsherinHindsight: The scene the series ends on consists of the three hedgehogs remotely flying cargo aircraft into the side of a skyscraper...
* HoistByTheirOwnPetard: In episode 5, "Mobodoon", the gang tries to defend the town from Robotnik by using their musical instruments, but the musical number they performed earlier drained their power.
* HoverBoard: Manic's, though Sonic was shown with one in a single episode.
* HulkSpeak: ARTT the robot talks like this, but in a strangely natural tone of voice, which is the complete opposite of the SWAT-bots.
* InNameOnly: The only things from the ''Franchise/SonicTheHedgehog'' games are Sonic, Robotnik, the Chaos Emerald and a few appearances by Knuckles.
* IdenticalGrandson: In "Mummy Dearest" the siblings find the tomb of a distant ancestor of theirs, who looks and acts just like Sonic.
* IdenticalStranger: In parallel universes, the main cast have doppelgangers.
* {{Idiosyncratic Wipe|s}}: Just the one: Sonic's guitar rotating toward and then away from the screen while an echoing chord plays.
* InstrumentOfMurder
* JerkWithAHeartOfGold: Despite his wealthy lifestyle, cowardice, and the threats to his life should he turn his back on Robotnik, Bartleby has helped the hedgehogs at times.
** In return, they broke him out of prison near the end of the series.
* KangarooCourt: One episode sees Bartleby being put on trial for aiding the resistance, with Robotnik as the judge, Sleet as the prosecutor, and for his defense attorney? ''Dingo''. [[spoiler: Of course the whole thing was a ruse to lure Sonia out...]]
* KleptomaniacHero: Manic.
* LaserGuidedAmnesia: Happens to Sonia in one episode.
* LeftHanging: [[http://www.bumbleking.com/forum/viewtopic.php?f=4&t=6219 Averted after 10 years of playing it straight]]... only for the fate of THAT to be left hanging too.
* {{Leitmotif}}: Aleena's theme, an ethereal electric guitar riff.
* LightningBruiser: Sonic.
* LoveTriangle: Started out with Bartleby and Cyrus competing for Sonia's affection, then became one between her, Cyrus and Knuckles.
* MadeOfExplodium: The SWAT-bots tend to explode whenever damaged.
* MadnessMantra:
-->'''Emerald-powered Dingo:''' CHAOS...I...WANT...CHAOS!
* MagicPants: In the episode "Sonic Tonic" when the side effect of the titular tonic sets in, Sonia and Manic's feet grow huge but their footwear just stretches to fit and when their feet go back to normal so does their footwear. This is averted with Sleet and Dingo, however.
* MamaBear: Queen Aleena shot down some Swatbots to save Manic from being roboticized.
* MeaningfulName: Sonia and Manic both make the word "Sonic" when "ia" and "ma" are removed from their respective names.
* MechaMooks: SWAT Bots.
* {{Mentor|s}}: The Oracle of Delphius.
* MessyHair: Manic has it.
* MindControlDevice: The darts in "Bug!"
* MirrorUniverse: The hedgehogs entered one where they were the tyrants and Robotnik was a Freedom Fighter. It ended with them [[HeelFaceTurn redeeming]] their evil counterparts. Strangely, there was no mirror Aleena.
* TheMole: Cyrus in his debut episode.
* MrViceGuy: Manic can't seem to get out of his old habit of stealing.
* MusicalAssassin: All three of the hedgehogs.
* MythArc: Later episodes had more of a StoryArc, with the hedgehogs meeting Knuckles and Cyrus, and Bartleby joining the side of good.
* MythologyGag: In the first episode, we can see Uncle Chuck and Sonic in Uncle Chuck's base from ''[[WesternAnimation/SonicSatAM Sonic the Hedgehog]]''. When Robotnik is taking over, we can see a statue of King Acorn (also from ''[=SatAM=]'') crumble.
* NeverSayDie: Averted in the second episode when the trio fail a training exercise.
-->'''Sonic:''' "I got us killed."
* NiceJobBreakingItHero: A lot of trouble could have been avoided if the Oracle hadn't told Robotnik about their plan to overthrow him.
* NoEnding: The show was cancelled before an ending could be written; the final episode doesn't resolve anything. [[http://www.bumbleking.com/forum/viewtopic.php?f=4&t=6519&start=30 So the comic will!]] Or, rather, it ''would've''...
* NonIdleRich: The Duke of Argonia, who uses his wealthy lifestyle to aid poor Mobian kids.
* OffModel: Plenty of weird faces, perspective and anatomy issues and cut-off[=/=]unfinished body parts populate the series.
** Knuckles suffered ''especially'' from this, as seen [[http://notanothersonicblog.tumblr.com/post/54504945452/so-many-things-wrong-with-this-sequence here]] and [[http://notanothersonicblog.tumblr.com/post/54895080953/knockles here]].
** At the start of "The Big Melt" Sonia's feet are much smaller than Sonic and Manic's, but at the end her feet are just as big.
* OneWingedAngel: A Chaos Emerald-powered Dingo turns into a giant, unstoppable blob who nearly destroys Mobius.
* PhotographicMemory: Sonia.
* ThePowerOfFriendship: This powers the hedgehogs' instruments.
* ThePowerOfRock
* PrinceCharmingWannabe: Bartleby Mink, though he didn't start like it; at first Sonia reciprocated his affections to a degree.
* ProtestSong: The band had a few in their repertoire, such as "Justice Calling" and "The Sound of Freedom".
* RemakeCameo: Phil Hayes, Creator/GaryChalk and Creator/IanJamesCorlett, who voice Bartleby, Dr. Robotnik and Cyrus respectively in this series, voiced Scratch, Grounder and Coconuts in ''WesternAnimation/AdventuresOfSonicTheHedgehog''.
* RePower: Famously super fast, Sonic gets...ThePowerOfRock.
* RichSuitorPoorSuitor: Bartleby of the high class, haughty variety, and Cyrus, the street smart resistance member. Sonia's also shown affection for Knuckles, who doesn't really fit into either category.
* RidiculouslyHumanRobots: While there are exceptions, such as Argus's roboticized form, most roboticized Mobians don't look much different from their regular selves. Some even look almost completely Mobian except for cybernetic eyes or limbs.
** Robotnik also created a lifelike hedgehog baby as part of a plan to invade Sanctuary.
* RoboticReveal: [[spoiler: Ifyoucan.]]
* RockTrio: The triplets, naturally, with Sonia playing keyboard instead of bass guitar.
* RoleReprisal: Jaleel White returns as the voice of Sonic and also voices Sonia and Manic.
** TheOtherDarrin: Though Sonic's singing voice is done by Creator/SamuelVincent.
* SadisticChoice: In the aptly-named "Sonia's Choice", she must choose whether to save Sonic or Manic from the roboticizer. Sonia chooses [[spoiler: Sonic]]...and Queen Aleena ends up saving [[spoiler: Manic]].
* SatisfiedStreetRat: Manic.
* ScoobyDoobyDoors: {{Downplayed}} when Sonic gets lost while navigating the Flying Fortress.
* ScienceIsBad: Surprisingly downplayed. In this show, unlike in WesternAnimation/SonicSatAM, Robotnik is much less of a polluting industrialist and mostly sees technology as a way to maintain his control over the planet. Therefore, there's much less of an incentive for him to pollute the entire planet purely for the sake of doing so. Granted, the places under his most secure control aren't paradise, but they're still livable, and it's heavily implied that the hedgehog's secret home base is located in Robotnik's capital city. That, and Sonic and Company have used futuristic technologies (i.e. a RV van, a hover board, motorcycle, several other vehicles) constantly in their fight against Robotnik. Furthermore, there are several incredibly beautiful and highly futuristic cities on Mobius.
* ScrewTheMoneyIHaveRules: A recurring theme on this show is aristocrats giving up their wealth to help the hedgehogs, such as Mindy and [[spoiler:Bartleby]].
* {{Shapeshifting}}: Dingo can morph into just about anything with Sleet's morphing device.
* ShoutOut:
** Manic's hoverboard looks like a Federation Scoutship from the ''Series/StarTrekTheNextGeneration'' movies.
** The end of "Bartleby the Prisoner" is one to ''Film/{{Casablanca}}''.
* SiblingYinYang: Sonia is an upper-class, responsible girl who hates getting dirty. Manic, on the other hand, is a laid-back street rat who's lived in the sewers most of his life.
* SilenceYouFool: Possibly this Robotnik's catchphrase in the show, usually used against Sleet and Dingo when they try to explain themselves about why they are incompetent.
* SitOnTheCamera: in episode "The Jewel in the Crown" when Dingo sits on Manic's remote controlled bug. "I think I sat on a bug."
* TheSmartGuy: Cyrus.
* SpoiledSweet: Mindy [=LaTour=].
* TheStarscream: Sleet and Dingo try to be this when they snatch a Chaos Emerald from Robotnik. It doesn't quite work out.
* StatusQuoIsGod: Played straight with the main story, especially as there was no finale, but averted with Bartleby joining the Resistance.
* StickyFingers: Manic.
* SurferDude: Manic.
* ThemeTuneCameo: Lots of times.
* TheRenaissanceAgeOfAnimation
* ThereWasADoor: Sleet and Dingo have an exchange in episode 2:
-->'''Sleet:''' Go in and help the metalhead. Go!
-->'''Dingo:''' Y-you mean through the door there?
-->'''Sleet:''' [[DeadpanSnarker No, through the wall, genius.]]
-->'''Dingo:''' [[SarcasmBlind Okey-dokey!]] *charges through the wall*
* ThoseTwoBadGuys: Sleet and Dingo.
* TotallyRadical
* TrademarkFavoriteFood: Again, chili dogs.
* TransformationRay: Sleet has one for use on Dingo.
* TrapIsTheOnlyOption: In "Wedding Bell Blues," the hedgehogs know Robotnik's wedding to Queen Aleena is a trap, but fall into it anyway on the off-chance Aleena is actually there.
** In another episode, in a call back to a ''Sonic [=SatAM=]'' plot, Robotnik challenges Sonic to a race. Sonia and Manic, figuring Sonic couldn't resist, show up to try and rescue him... except he knew it was a trap and ''didn't'' show, and ''they'' have to be rescued.
* UnwillingRoboticization: Similar to how it works in WesternAnimation/SonicSATAM, with one major difference being that most of the time, beings that undergo roboticization come out looking like cyborgs and not full-fledged robots. However, the minds of roboticized beings are still mentally enslaved to Robotnik and this control can only be broken temporarily.
** Also, Robotnik used the roboticizer much more sparingly in this show, treating it more as a punishment for rebellion or failing to carry out his orders, rather than an umbrella treatment for all living creatures. Most people are not roboticized and Robotnik employs two unroboticized bounty hunters who are threatened several times with the treatment but are never actually subjected to it.
*** Though it should be noted Dingo appears to have a roboticized leg, wrists and hands, though this is never expanded upon or even pointed out.
**** Although at one point, Dingo did not have a robotic leg (his leg's actually normal) when he tried to sneak away from Robotnik and Sleet near the end of ''New Echidna in Town''.
* UpperClassTwit: Bartleby Mink.
* WeddingSmashers: The hedgehogs try and crash Queen Aleena's forced marriage to Robotnik, except there was never one to begin with as she didn't show.
* WhatKindOfLamePowerIsHeartAnyway: Sonic has SuperSpeed. Sonia has SuperStrength. Manic...can pick locks.
** HeartIsAnAwesomePower: Which helps a lot in sneaking in and out of Robotnik's base.
* WhyDidItHaveToBeSnakes: Sonic's fear of water comes into play in a few episodes.
* YouAreNotReady: According to the prophecy, Queen Aleena can't reunite with her children until the right time comes.

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