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Season guide

Sonic Underground: Season 1

40 episodes Premiered Aug 30, 1999 Updated Jul 22, 2026
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Episodes

S1·E1

Beginnings (Origins, Part 1)

Aug 30, 1999

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 Que

S1·E2

To Catch a Queen

Aug 31, 1999 · 30 min

The Hedgehogs begin to learn the important lessons of what it takes to be a freedom fighter.

S1·E3

Mobodoon

Sep 1, 1999 · 30 min

Manic, Sonic and Sonia must end their training early when Robotnik threatens the Oracle and takes a member of the resistance hostage.

S1·E4

The Price of Freedom

Sep 2, 1999 · 30 min

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

S1·E5

Underground Masquerade

Sep 3, 1999

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 Und

S1·E6

Tangled Webs

Sep 6, 1999 · 30 min

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 s

S1·E7

The Deepest Fear

Sep 7, 1999

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 Sque

S1·E8

Who Do You Think You Are

Sep 8, 1999

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 t

S1·E9

The Last Resort

Sep 9, 1999

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 h

S1·E10

Come Out Wherever You Are

Sep 10, 1999

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 construct

S1·E11

Winner Fakes All

Sep 13, 1999

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 compe

S1·E12

A Hedgehog's Home Is Her Castle

Sep 14, 1999 · 30 min

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 headquar

S1·E13

Artifact

Sep 15, 1999

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 inf

S1·E14

Bug!

Sep 16, 1999

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. Soni

S1·E15

Sonic Tonic

Sep 17, 1999

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,

S1·E16

Friend or Foe?

Sep 20, 1999

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, w

S1·E17

Head Games

Sep 21, 1999

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, w

S1·E18

When in Rome...

Sep 22, 1999 · 30 min

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 per

S1·E19

The Jewel of the Crown

Sep 23, 1999

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

S1·E20

Three Hedgehogs and a Baby

Sep 24, 1999

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 t

S1·E21

Dunes Day

Sep 27, 1999

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 th

S1·E22

Mummy Dearest

Sep 28, 1999

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 b

S1·E23

Hedgehog in the Iron Mask

Sep 29, 1999

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

S1·E24

Six Is a Crowd

Sep 30, 1999

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 parall

S1·E25

Flying Fortress (Chaos Emerald Crisis, Part 1)

Oct 1, 1999 · 30 min

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 investigat

S1·E26

Wedding Bell Blues

Oct 4, 1999

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,

S1·E28

Getting to Know You (Origins, Part 2)

Oct 6, 1999

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 s

S1·E29

New Echidna in Town (Chaos Emerald Crisis, Part 3)

Oct 7, 1999

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 eve

S1·E30

Harmony or Something (Origins, Part 3)

Oct 8, 1999

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 int

S1·E31

Country Crisis

Oct 11, 1999

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, Ro

S1·E32

Haircraft in Space

Oct 12, 1999

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

S1·E33

Healer

Oct 13, 1999

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 ne

S1·E34

Sonia's Choice

Oct 14, 1999

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 heirloom

S1·E35

The Big Melt

Oct 15, 1999

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 s

S1·E36

Sleepers

Oct 18, 1999

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

S1·E37

Bartleby the Prisoner

Oct 19, 1999

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 m

S1·E38

The Art of Destruction

Oct 20, 1999 · 30 min

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 m

S1·E39

The Pendant

Oct 21, 1999

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 peninsul

S1·E40

Virtual Danger

Oct 22, 1999

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 inter