[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/Sonic_Underground_7556.jpg]]
[[caption-width-right:320:They made a vow - their mother will be found!]]

''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, 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 three]] [[WesternAnimation/AdventuresOfSonicTheHedgehog other]] [[WesternAnimation/SonicBoom western]] [[WesternAnimation animated]] series based on Sonic the Hedgehog, the {{Anime}} series ''Anime/SonicX,'' the {{OVA}} ''Anime/SonicTheHedgehogTheMovie,'' the [[Film/SonicTheHedgehog2018 the upcoming film adaptation]] or the game that helped to [[CutShort kill it off]] that same year, ''VideoGame/SonicAdventure''.

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 [[ComicBook/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.
----
!!''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 grody-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.
* BellyDancer: Sonia during the "Cosmic Dance" song in "The Jewel in the Crown".
** Another shows up as part of the Resistance in "Dunes Day".
** Sonic and Manic [[WholesomeCrossdresser dress as belly-dancers]] to [[WeNeedADistraction distract Sleet]] in one episode.
* 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 [[CutLexLuthorACheck 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, 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.
** Sonia as well, at first. Her brothers frequently make fun of her for being spoiled.
* 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: 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. Invoked as she was a spy for Robotnik: she would lure her customers into blabbing secrets, then record them on an internal tape recorder.
* ColorCodedForYourConvenience: The lasers their instruments shot were color-coded.
* ChromaticArrangement
* CreepyMonotone: ART, to a point. Also Manic when under Robotnik's control in "Bug!"
* CutShort: They made a vow their mother will be found... but she never was. The series ended early.
* DeadpanSnarker: Sleet.
* DeusExMachina: Queen Aleena made sporadic appearances to save the hedgehogs at times.
* DishingOutDirt: Manic, who can cause earthquakes with his drumming.
* 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: The theme song describes the show's premise and what the hedgehogs hope to accomplish.
* FailureIsTheOnlyOption: 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. Similarly, Sonic, Sonia and Manic never succeed in reuniting with their mother.
* FatBastard: Sonic's corrupted self in "Six is a Crowd".
* FeudalFuture: Robotnik basically 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 are almost never thought or spoken of again.
* FullyAbsorbedFinale: The series' story was meant to get a conclusion through the ''[[ComicBook/SonicTheHedgehog Archie Sonic the Hedgehog]]'' comics, but it ended up being canceled.
* 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.
* HoverBoard: Manic's, though Sonic was shown with one in a single episode.
* HulkSpeak: ART 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, the Floating Island, 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 a parallel universe, the main cast have alignment-flipped doppelgangers.
* {{Idiosyncratic Wipe|s}}: Only one. Sonic's guitar rotating toward and then away from the screen while an echoing chord plays.
* InstrumentOfMurder: Sonic, Sonia, and Manic use their music as a weapon at times, as Sleet and Dingo can't stand it.
* 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...]]
-->'''Dingo''': Your honour, my client here is innocent... although he looks like a dirty traitor to me.
-->'''Sonic''': With a defense like Dingo, who needs a prosecutor?
* KleptomaniacHero: Manic. Justified as he was raised by thieves and really doesn't know any better.
* 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.
* LighterAndSofter: Though not as light as ''Adventures'', it has a much lighter and more comedic tone compared to ''[=SatAM=]''. Being a musical helps.
* 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.
* MaliciousMisnaming: Like ''WesternAnimation/SonicSatAM'' and ''WesternAnimation/AdventuresOfSonicTheHedgehog'' before it, the show has Sonic constantly refer to Robotnik as "Robuttnik", and occasionally "Buttnik". The triplets occasionally get in on it as well.
-->'''ART''': 'Buttnik?' Oh. [[DontExplainTheJoke Robotnik. Buttnik]]. [[CreepyMonotone Ha ha ha. That is funny.]]
* 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!", which turned one into a Robotnik spy.
* 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.
* MoralDissonance: In "Haircraft in Space", members of the aristocracy are hypnotized by a robotic stylist at a hair salon, forced into admitting their negative thoughts concerning Robotnik, which are recorded and retrieved by Sleet and Dingo. Sonic and Manic want to let the robot get captured again, thinking that Bartleby will be fine and the rest would get what they deserved for gossiping, until Sonia reveals she was also affected.
* 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:
** Sonic being in a rock band was a scrapped idea from when the very first ''Sonic'' game was in development.
** In the first episode, we can see Uncle Chuck and Sonic in Uncle Chuck's base from ''WesternAnimation/SonicSatAM''. 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. The planned comic conclusion was also shelved.
* 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. [[LaserGuidedAmnesia Except for the one episode where she loses it]].
* ThePowerOfFriendship: This powers the hedgehogs' instruments.
* ThePowerOfRock: Quite literally, as the triplets' instruments double as laser weapons or, in Manic's case, earthquake generators.
* 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".
* RedemptionEqualsDeath: In "The ART of Destruction", the titular learning robot is converted to the Resistance via ThePowerOfRock. [[spoiler:At the climax of the episode, ART holds back a [[TheWallsAreClosingIn closing-wall trap]] long enough for the triplets to escape, and is crushed and killed]].
* 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]] was roboticized, but retained his free will, similar to Uncle Chuck in [=SatAM=].
* 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. About the only key difference is that Sonic's singing voice is done by Creator/SamuelVincent.
* SadisticChoice: A LighterAndSofter version. In the aptly-named "Sonia's Choice", she must choose whether to save Sonic or Manic from the roboticizer. Sonia chooses [[spoiler: both! Queen Aleena ends up saving Manic anyway]].
* 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 hedgehogs' 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 this version of 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: Arguably Robotnik's catchphrase in the show, usually used against Sleet and Dingo when they try to explain their latest failure.
* SitOnTheCamera: in episode "The Jewel in the Crown" when Dingo sits on Manic's remote controlled bug. "I think I sat on a bug."
* SlidingScaleOfAdaptationModification: The series is a Type 1 (InNameOnly) adaptation of the video games.
* TheSmartGuy: Cyrus.
* SpiritualSuccessor: The series received one in ''WesternAnimation/SpacePOP'', a girl-targeted show about royalty going underground as a rock band to search for their missing parents against a dictator with MechaMooks.
* SpoiledSweet: Mindy [=LaTour=]. Sonia as well to some extent.
* 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 just can't stop himself from stealing at times.
* SurferDude: Manic, complete with hoverboard.
* 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: Sonic, as in [[WesternAnimation/AdventuresOfSonicTheHedgehog the previous]] [[WesternAnimation/SonicSatAM two shows]], but Manic also gets in on the act, using nonsensical adjectives like "crashin'" and "rippin'" as well as "bogus".
* 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 ''[=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.
* TricksterMentor: The Oracle of Delphius definitely fits: he speaks in riddles more often than not, transports the hedgehogs into a MirrorUniverse where they're the bad guys to teach them a lesson, and when called out on it, responds with an absolute gem:
-->'''Sonic''': Don't you ever just give a straight answer?
-->'''Oracle''': What do you think?
* 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 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.
* UpperClassTwit: Bartleby Mink.
* VileVillainLaughableLackey: Dingo was DumbMuscle and less intelligent than his partner mercenary Sleet.
* WalkThisWay: [[LampshadeHanging Lampshaded]] in "A Hedgehog's Home is Her Castle".
-->'''Sonic''': "I'm waiting for you to say 'walk this way'." [''does a SillyWalk'']
* 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.
* WhatMeasureIsANonHuman: The show is pretty NeverSayDie usually, roboticizing characters instead of killing them. Robots who side with the good guys are sometimes destroyed, including Hip, the fake baby hedgehog who had developed a fondness for Manic, and ART, who saves Manic's life. ART is at least mourned, but when Hip is destroyed everyone is merely mad at Robotnik for tricking them. Then again, Hip never had a chance to express its feelings, being a baby.
* WhyDidItHaveToBeSnakes: Sonic's fear of water comes into play in a few episodes.
-->'''Sonic''': Why is it always water?
* YouAreNotReady: According to the prophecy, Queen Aleena can't reunite with her children until the right time comes.
* YouHaveFailedMe: Subverted in the second episode. Robotnik almost roboticizes Sleet and Dingo after their initial failure to capture the hedgehogs, but instead decides to give them "one last chance".

----