This page is for Cosmo the Seedrian, or more commonly known as just "Cosmo", from ANY person's continuity.

If you want to see her canon page, go here

Cosmo the Seedrian
Biographical Information

8 (Most fanfics-present)

11 (Sonic Rush 3)

13 (MegaSonic)

14 (Sonic the Hedgehog: Crystals of Soleanna)

18 (as an adult; The New Hero)


Chronicles Commented By Cosmo and Sonic's Reality Check

  • Miles Tails Prower (boyfriend)
  • Galaxina The Seedrian (older sister)
  • Daisy the Seedrian (sister)
  • Starla the Seedrian (sister)
  • Violet the Seedrian (sister)
  • Landar the Seedrian (brother)
  • Zelkova the Seedrian (brother)
  • Bay Leaf the Seedrian (brother)
  • Rosetta the Seedrian (daughter)
  • Hertia the Seedrian (mother)
  • Lucas the Seedrian (father)

Hikaru's Fanfics

Sonic Angels

Bita's Universe

Gurahk's Universe

The New Hero

  • Miles "Tails" Prower (Love Interest, Later Husband)
  • Albert Williams (Brother-In-Law)
  • Wilbur Williams (Brother-In-Law)


  • Dr. Mikhail Sergeyevich Cossack (Adoptive father)
  • Kalinka Cossack (Adoptive sister)
  • Ran Cossack (Adoptive brother)

PoKeLegends1's Continuity

  • Charmy Bee (Future husband)
  • Nectar the Beedrian (Future daughter)

Sonic the Hedgehog: Crystals of Soleanna

Marshalia13's Universe

  • Ben "Mutt" Muttski (love interest)
  • Earthia the Seedrain (mother)
  • Lucas the Seedrain (father)
  • Galaxina the Seedrian (older sister)
  • Sir Grodus 
Romantic Interests
  • Tails
  • Knuckles the Echidna (Previous love-interest in Sonic X)
  • Charmy  (PoKeLegends1 continuity)
  • Ben "Mutt" Muttski (Marshalia13's Universe)
Physical Description
Species Seedrian
Gender Female
  • Hair: Green
  • Eyes: Blue
Political Alignment and Abilities
  • Team Cosmo
  • Knothole Freedom Fighters
  • Treasure Team Tango

Chaos powers in new story chaos radiation

The New Hero

  • The power to control nature


Chronicles Commented By Cosmo

Taking place after Cosmo's death in Sonic X, Cosmo reunites with her mother Hertia, her sister Galaxina, along with several other Seedrian family members. She witnesses some events that transpire within the fanfiction timelines of Heroes From An Old World and Sonic Chronicles: Wrenched Into Oblivion while staying within the spirit world. She is still confused on what is going on, as a new Seedrian (Nebula from Heroes From An Old World) has shown up, along with the presence of a dangerous god named Scaith (also HFAOW.) Because of Scaith's return, the Metarex's trial (which would've had them sent into the Shadow Realm for their deeds) is put off until Scaith is resealed, causing anxiety among the Seedrians. So far, DiZ (from the Kingdom Hearts series) has encountered Dark Oak, asking about an entity named "X" that might be another Metarex, but it is unknown so far if X is indeed a Metarex or not.

As of recently, she found out she might be able to return to her homeworld. It has also been found out that she might have some sort of impact on the timeline that the gods themselves cannot figure out as of yet...

Sonic Chronicles series

Sonic Chronicles: Wrenched Into Oblivion

While Cosmo's spirit is in the heavens, her body remains as a seedling inside a plant pot. Her seed body is currently held prisoner by Marluxia and Larxene of Organization XIII (from Kingdom Hearts, as this fic is a Ratchet And Clank/Sonic The Hedgehog/Kingdom Hearts crossover), and only Tails knows this, but the base Marluxia and Larxene are at is inaccessible to Tails at the moment.

Cosmo also appeared to Tails in a dream, although it is unknown if this was the real Cosmo or a fabrication of her fron Tails's memories.

Heroes From An Old World

Cosmo is referenced (without her name) whenever The Scourge (not Scourge the Hedgehog) is reading over an old tome that chronicled Sonic's heroism in his past.

Sonic X: For True Story

This fic is a 'what-if' fic, stemmed from the timeline of Sonic X Episode 76. So far, Cosmo and the group tried to fire the Master Emerald-powered blast at Final Nova, like in Sonic X. However, in this what-if version, Nazo (from Sonic: Nazo Unleashed) is re-released; it is speculated by Tails that the Metarex's negative energy Emeralds might have done this. Nazo is about to kill Cosmo and Tails as retaliation for Tails helping Hyper Shadic defeat him last time, but the appearance of a Zone Cop stops him. Cosmo watches on in confusion as the Zone Cop briefly swats away Nazo, while Final Nova begins attacking as well. Soon enough, after a confusing fight between Nazo, Final Nova, and Shadow, a large Chaos Control occurs which damages Nazo and sends the others away. Nazo uses the Planet Eggs and sinks into the watery planet to heal his wounds, as he can only do his normal regenerative process with the power of 6 Chaos Emeralds. As for Cosmo, she and the others are teleported back to Mobius, although she had fallen unconscious due to the shock of the Chaos Control.

Sonic Chronicles: The Shadow Zone

In this sequel to The Dark Brotherhood (which is produced by Square Enix instead of Bioware), Cosmo plays a very important role in the story. Here, she once again serves as Tails' love interest.

The New Hero

Cosmo—along with Sonic the Hedgehog—plays an important roll. While Tails was absent looking for her, the plant that Sonic gave to him after the battle against the Metarex shined and shaped into Cosmo herself. Because Sonic was in the workshop (where she transformed back to her normal shape), he told Cosmo about Tails' fate, which made her eternally depressed. While Sonic and the others are going after Eggman, Cosmo had the fear that her friends are in danger, so she wanted to go and help them, but upon going outside, Eggman captured her—along with Sonic and friends—with his new army of robots, the Electrons. 10 years later, Cosmo, along with Sonic and Knuckles, escaped from the Eggman Empire with the help of T-Pup in order to look for Tails. Upon crash-landing on the planet Nimbus, Cosmo and Tails finally reunited together, and expressed their love with each other. Although later, Cosmo told Tails about the danger of Mobius, but Tails didn't really believed her until Sonic and Knuckles came and warned him about it.


Cosmo was revived by Dr. Cossack using her ashes and a machine. She has become a daughter to Dr. Cossack and is loyal to him, she has fallen into depression when she found out that Tails has found someone else. She was rescued by Bass when she was captured by Dr. Wily for experiments.

06civic68pa's Universe

Main Article: Cosmo the Seedrian (Marshalia13's Universe)

BearfootTruck's Universe

Cosmo makes a cameo appearance in the "Sonic Says" segment of A Dark Birthday, where she receives a beat-up music box from Tails and kisses him for it.

Cosmo is set to make an appearance in the upcoming "Sonic War Zone". Her role is yet to be determined.

Sonic the Hedgehog: Crystals of Soleanna

Six years after Sonic X ended, Cosmo and Tails get married and have 4 children, called Chad & Chill the Seedrifoxes, Alexis the Seedrian and Halinor Prower. She later joins Team Sonic and start a private house nobody is allowed to enter without a secret code. However, when a massive chaos outbreaks in both Mobius and Soleanna, it's their mission to turn the worlds normal again by collecting all the Infernal Crystals to restore the kingdoms again and reveal who actually Blossom's father is.


Cosmo is generally described as a beautiful alien girl with plant-like features. She has green, leafy hair and tan-colored skin. Along with a green dress with a white petal like skirt with green tips at the end and uses them as a parachute from falling down. She wears white tights and green ballet shoes. Like Mobians, she has five toes on each foot.

Flash of the shadows

She only appears in the anti saga for the support of sair and ray ray calls her little green. (like in Dragon ball Abridged of Deneda being called little green by krillen)

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