Sonic Underground
S01:É01 - S01:E01 - Wedding Bell Blues
Robotnik announces that he will marry Queen Aleena in a plot to become the king of Mobius.
S01:É02 - S01:E02 - To Catch a Queen
Argus, a captain of the Queen's guard, is captured by Sleet and Dingo before he can reach the secret rendezvous where he was to meet Queen Aleena.
S01:É03 - S01:E03 - Mobodoon
Sonic, Sonia and Manic return to their birthplace, Mobodoon, a beautiful, festive town.
S01:É04 - S01:E04 - The Price of Freedom
Sonia travels to east Mobius to visit her friend Mindy at the LaTour estate.
S01:É05 - S01:E05 - Underground Masquerade
Sleet and Dingo plan to collect the taxes owed to Robotnik from the Duke of Velcronia but keep it for themselves.
S01:É06 - S01:E06 - Tangled Webs
The sinister Robotnik blackmails Cyrus, an old friend of Sonic's, by holding his father hostage.
S01:É07 - S01:E07 - 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.
S01:É08 - S01:E08 - Who Do You Think You Are
Queen Aleena's royal journals are rumored to be buried under a palace in the city of Tashistan.
S01:É09 - S01:E09 - Last Resort
While lost in the wastelands of Mobius, Sonic, Manic and Sonia stumble upon an oasis called Lake Valley Resort.
S01:É10 - S01:E10 - 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.
S01:É11 - S01:E11 - Winner Fakes All
Robotnik organizes a track meet to lure Sonic into a trap.
S01:É12 - S01:E12 - A Hedgehog's Home Is Her Castle
The Hedgehogs receive a message they believe is from their cousin.
S01:É13 - S01:E13 - Artifact
The Hedgehogs steal historical artifacts of Mobuis from Robotnik before he can pawn them off at an auction.
S01:É14 - S01:E14 - Bug
A faction of the Freedom Fighters is wiped out by a swarm of metallic fly-bots.
S01:É15 - S01:E15 - 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.
S01:É16 - S01:E16 - Friend or Foe
The Hedgehogs converge on the Floating Island, in their latest attempt to find their Mother.
S01:É17 - S01:E17 - 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.
S01:É18 - S01:E18 - When in Rome...
Sonic becomes frustrated that maybe all of their efforts of fighting for freedom seem futile.
S01:É19 - S01:E19 - The Jewel of the Crown
Robotnik has his sights set upon Queen Aleena's crown jewel, which glows as it is moved closer her.
S01:É20 - S01:E20 - 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.