Series · 1999
Sonic Underground

The series
Sonic, Sonia, and Manic are the children of Queen Aleena Hedgehog, the rightful ruler of Mobius, and are pursued relentlessly by Doctor Robotnik and his bumbling bounty hunters sidekicks, Sleet and Dingo. As infants, the siblings were separated and placed in hiding to fulfill a prophecy made by the Oracle of Delphius that the triplets would grow up to find their estranged mother, overthrow Robotnik, and take their places once more as Mobius' rightful rulers.
Episodes
Season 1 · 40 episodes · 1999
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Episode 130 Aug 1999
Beginnings (Origins, Part 1)
The history of the Underground is told in detail, from the fall of Mobotropolis to the rise of Robotnik. Included, is a prophecy, as told by the Oracle of Delphius, that caused Queen Aleena to give up her own children so that all people of…
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Episode 231 Aug 199930m
To Catch a Queen
The Hedgehogs begin to learn the important lessons of what it takes to be a freedom fighter.
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Episode 31 Sep 199930m
Mobodoon
Manic, Sonic and Sonia must end their training early when Robotnik threatens the Oracle and takes a member of the resistance hostage.
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Episode 42 Sep 199930m
The Price of Freedom
Sonia travels to east Mobius to visit her friend Mindy at the LaTour Estate. After being given a watch by her friend Mindy, Sonia discovers that these popular timepieces are really monitoring devices for the Robotnik Intelligence Agency an…
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Episode 53 Sep 1999
Underground Masquerade
Sleet and Dingo plan to collect the taxes owed to Robotnik from the Duke of Velcronia but keep it for themselves. To avoid the wrath of Robotnik, Sleet and Dingo infiltrate the Underground to corral Manic and friends to the commit the crim…
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Episode 66 Sep 199930m
Tangled Webs
The sinister Robotnik blackmails Cyrus, an old friend of Sonic's, by holding his father hostage. Robotnik makes Cyrus gain the Hedgehogs trust and then has Cyrus convince them to save his father. Cyrus reluctantly informs Robotnik of the r…
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Episode 77 Sep 1999
The Deepest Fear
On a trip to Port Mobius, Sonic, Manic and Sonia are told that ships are sinking due to the Mobian sea-beast. The legendary story becomes fishy when the Hedgehogs meet Captain Squeegee who informs them of a scam in which townspeople must r…
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Episode 88 Sep 1999
Who Do You Think You Are
Queen Aleena's royal journals are rumored to be buried under a palace in the city of Tashistan. As Sonic and his siblings scour the city in search of the scrolls, Sonia gets into trouble when she is accidentally knocked in the head during …
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Episode 99 Sep 1999
The Last Resort
While lost in the wastelands of Mobius, Sonic, Manic and Sonia stumble upon an oasis called Lake Valley Resort. Although Sonic is impressed with the beauty of this safe haven, he has a sinking feeling that this village may be under the sco…
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Episode 1010 Sep 1999
Come Out Wherever You Are
Sonia is invited to a debutante ball, but before she can be officially announced to society, she and her brothers, Manic and Sonic have an important mission. Robotnik has constructed an evil weapon that will capture and robotisize all memb…
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Episode 1113 Sep 1999
Winner Fakes All
Robotnik organizes a track meet to lure Sonic into a trap. Robotnik is sure that Sonic will not sit out on a challenge of quickness. Sonia and Manic are also aware of Sonic's competitive nature and advise Sonic not to enter the event due t…
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Episode 1214 Sep 199930m
A Hedgehog's Home Is Her Castle
The Hedgehogs receive a message they believe is from their cousin. In the message, a castle is left to Sonia, who revels in the idea of having a castle for the Underground headquarters. Sonic, Manic and Sonia arrive at the castle only to s…
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Episode 1315 Sep 1999
Artifact
The Hedgehogs steal historical artifacts of Mobuis from Robotnik before he can pawn them off at an auction. Sonic and Sonia take one of the pieces to a university professor who informs them that the artifact is actually a bomb from the Mob…
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Episode 1416 Sep 1999
Bug!
A faction of the Freedom Fighters is wiped out by a swarm of metallic fly-bots. When Manic goes in search of the insects, he is stung with serum, making him loyal to Robotnik. Sonia finds Manic communicating a radio message to Robotnik and…
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Episode 1517 Sep 1999
Sonic Tonic
A speed enhancing fluid deemed Sonic Tonic is created by Robotnik to make him as fast as Sonic so that he may finally catch him. Robinik's plan is successful and Sonic is captured, yet when Dingo begins to feel the side effects of the toni…
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Episode 1620 Sep 1999
Friend or Foe?
The Hedgehogs converge on the Floating Island, in their latest attempt to find their Mother. Sleet and Dingo also have an interest in this island that involves the Chaos Emerald, which is the island's life-force. But, before either party c…
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Episode 1721 Sep 1999
Head Games
As Sonic begins to chow chili dogs for a snack, he finds a message in the sack from his mother urging him to head to Speedster Island. When he, his brother and his sister arrive, what they encounter is an ancient sanctuary that is about to…
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Episode 1822 Sep 199930m
When in Rome...
Sonic becomes frustrated that maybe all of their efforts of fighting for freedom seem futile. Sonia suggests that they go to Oracle, the spiritual guide, to put everything into perspective. The Oracle makes a deal with the Hedgehogs, stati…
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Episode 1923 Sep 1999
The Jewel of the Crown
Robotnik has his sights set upon Queen Aleena's crown jewel, which glows as it is moved closer her. Sonic, Manic and Sonia plan to recover the jewel from the merchant owner before Robotnik, not only to find their mother, but to protect her…
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Episode 2024 Sep 1999
Three Hedgehogs and a Baby
Sonic, Manic and Sonia find an abandoned baby in an alley and begin a search for the baby's parents. Manic grows particularly fond of the child and decides that instead of taking the baby to a shelter as Sonic and Sonia ordered, the baby w…
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Episode 2127 Sep 1999
Dunes Day
Sonic and his siblings travel to the outskirts of Mobius to recruit a tribe of nomads for the Resistance. The Hedgehogs van breaks down and they are saved by the tribesman. Once they return to the camp, Manic discovers that the chief has b…
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Episode 2228 Sep 1999
Mummy Dearest
Sonic, Manic and Sonia invade Robotnik's lair to retrieve the Hedgehog crest. After the book is reclaimed, they discover that this book contains directions to a scroll that could be an important tool to overthrow Robotnik. The scroll is he…
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Episode 2329 Sep 1999
Hedgehog in the Iron Mask
The Hedgehogs latest quest to find their mother takes them to the prison tower where they encounter a masked stranger who insists he is family. This stranger is actually being used as bait for another attempt by Robotnik to capture them. T…
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Episode 2430 Sep 1999
Six Is a Crowd
The Oracle advises the Hedgehogs to undertake a mission which could reveal answers about their future. Sonic, Manic and Sonia are thrown into a universe that almost seems to parallel their own, however in this dimension, they are not the i…
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Episode 251 Oct 199930m
Flying Fortress (Chaos Emerald Crisis, Part 1)
What is supposed to be a vacation for Sonic, Manic and Sonia turns into a battle to save Mobius when Robotnik attacks with his newest weapon - the Flying Fortress. Sonic investigates the ship thinking the weapon can be destroyed by removin…
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Episode 264 Oct 1999
Wedding Bell Blues
Robotnik announces that he will marry Queen Aleena in a plot to become the king of Mobius. Upon hearing the alarming news and shocked that their enemy will become their stepfather, Sonic, Manic and Sonia become suspicious that this wedding…
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Episode 275 Oct 199930m
No Hedgehog Is an Island (Chaos Emerald Crisis, Part 2)
Sleet and Dingo escape the Flying Fortress with the Chaos Emerald. In a fight over who will control the Emerald's power, Sleet and Dingo drop and break the Emerald in two. Instantly, a rash of earthquakes and other natural disasters are sp…
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Episode 286 Oct 1999
Getting to Know You (Origins, Part 2)
The Hedgehogs begin to learn the important lessons of what it takes to be a freedom fighter. The Oracle provides teachers to guide Sonic, Manic and Sonia to develop the necessary skills to recognize the power that comes from within. The He…
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Episode 297 Oct 1999
New Echidna in Town (Chaos Emerald Crisis, Part 3)
Knuckles reluctantly makes a deal with Robotnik to turn over Sonic and his family in exchange for finding the Chaos Emerald that will save Mobius. Knuckles soon regrets that he ever trusted the evil dictator after Robotnik begins to follow…
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Episode 308 Oct 1999
Harmony or Something (Origins, Part 3)
Manic, Sonic, Sonia must end their training early when Robotnik threatens the Oracle and takes a member of the resistance hostage. During the rescue mission, the Hedgehogs fall into trouble and begin to place blame upon each other for ever…
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Episode 3111 Oct 1999
Country Crisis
Queen Aleena advises the Hedgehogs to travel to a valley of Mobius so that they can bring about peace between two contingents of the resistance that have split. In the meantime, Robotnik is able to build a dam that is dangerous to the peop…
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Episode 3212 Oct 1999
Haircraft in Space
Robotnik is using the local hairdresser, Doo-bot, to get information on the citizens that are against him. Sonia becomes a victim of the Doo-bots trance during a shampoo and while under the spell, divulges important information that could …
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Episode 3313 Oct 1999
Healer
A self proclaimed scientist has come to Robotropolis with a device that will reverse the effects of Robotnik's roboticizer. Sonia, Manic and Sonia attend a demonstration of this new technology where Sonia decides she can use it to help her…
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Episode 3414 Oct 1999
Sonia's Choice
Robotnik has arranged a museum exhibit of the Royal family goblets. Knowing that Sonic, Sonia and Manic will want to reclaim their family's treasures, Robotnik expects the heirlooms will serve as perfect bait to finally capture the Hedgeho…
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Episode 3515 Oct 1999
The Big Melt
The Hedgehogs vacation is interrupted by the news of Robotnik's latest weapon. They are shocked as the submarine melts the icy landscape from under their feet. The Hedgehogs then scurry to locate the lethal submarine before the entire plan…
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Episode 3618 Oct 1999
Sleepers
On a mission in a distant sector of Robotropolis, the Hedgehogs are informed that freedom fighters have disappeared and are going to be roboticized. Sonic races to save his friends, but he is too late. The group of freedom fighters have be…
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Episode 3719 Oct 1999
Bartleby the Prisoner
Robotnik's new weapon, Art, is the enforcer of Robotropolis new eradication policy. Art's objective is to destroy everything in sight, including Sonic, Manic and Sonia. The giant mechanical beast is seemingly unstoppable until he overhears…
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Episode 3820 Oct 199930m
The Art of Destruction
Robotnik's new weapon, Art, is the enforcer of Robotropolis new eradication policy. Art's objective is to destroy everything in sight, including Sonic, Manic and Sonia. The giant mechanical beast is seemingly unstoppable until he overhears…
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Episode 3921 Oct 1999
The Pendant
The newly discovered Emerald Peninsula is a perfect place for Robotnik to add slaves to his empire. Sonic, Sonia and Manic are alerted of Robotnik's plan to transplant the peninsula's inhabitants and turn to a fortune teller for help. The …
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Episode 4022 Oct 1999
Virtual Danger
Sonic and Manic play a game of virtual reality to enhance their pilot skills. When the two brothers decide to put their practice to use, they fly in a successful mission that intercepts a supply ship from Robotnik. To put the Hedgehogs gam…




