"So Long Sonic" is the seventy-eighth and final episode of the anime series, Sonic X. It first aired on 18 April 2005 and 6 May 2006 in France and the United States, respectively.
- Sonic the Hedgehog
- Miles "Tails" Prower
- Knuckles the Echidna
- Amy Rose
- Cream the Rabbit
- Dark Oak
- Chris Thorndyke
- Shadow the Hedgehog
- Doctor Eggman
- Vanilla the Rabbit (Japanese version only)
- Rouge the Bat
- Espio the Chameleon
- Charmy Bee
- Vector the Crocodile
- Lindsey Thorndyke
- Nelson Thorndyke
- "Gotta Go Fast" - Opening theme (USA and CAN)
- "Sonic X" - Opening theme (AUS, NZ and UK)
- "Gotta Go Fast" (shortened) - Closing theme
The episode starts off with Vanilla stopping by the Chaotix Detective Office to thank the Chaotix for all that they did for her and Cream. Amy and Cream then bring a whole bunch of snacks to Tails to try and cheer him up. (Note: This entire first part, almost four minutes long, was not shown in the English dub of the episode.)
Chris then flashes back to the point just when the planet with Cosmo on it was being destroyed. Lucas is seen following Earthia to peace. Suddenly, the planet begins to expend all of its energy. Punching Super Sonic out of the way (which looked very painful for Sonic), Super Shadow uses the last of his energy to perform Chaos Control to stop time, giving everyone else a chance to escape before Dark Oak's corruptive Planet Egg explodes. Eggman then worries that Shadow may not have survived the Chaos Control he did to save everyone, and he begins to feel some remorse for Shadow. Meanwhile, Sonic approaches Tails with only a seed from Cosmo. Tails, already upset about losing her, finally falls into Sonic's arms, crying as they fly away. The Planet Eggs are returning to their respected home planets in a flash of many lights.
Back on their homeworld, Chris and Knuckles have a little discussion about what's next for Chris, and they fall along the lines of where Chris's home would be now that he can't go back since the Master Emerald had been reduced to several powerless Emerald Shards for the time being. Rouge is seen in Eggman's ship staring at Shadow's pod. After a run-in with Eggman, Rouge suspects that he knows something about Shadow's whereabouts. Near the end of the episode, Eggman shows Chris an egg-shaped pod that will take him home, but there's a catch: Chris only has three minutes to return home, or else he could be stuck in Sonic's world! Chris has no time to say goodbye to his friends, just as Eggman planned. Chris then leaves Sonic's universe via Eggman's pod. Once Chris is gone from sight, Eggman says that with Chris out of the way, he can continue in his creation of the Eggman Empire.
Sonic's last words were "I won't forgive you, Eggman!" ("Life never stays slow around here for long, thank goodness! Watch out, Eggman! I'm coming at'cha, full speed!" in the English dub). We then see a pot with a seed (apparently the one Sonic found) in it. The episode ends as the Egg pod with Chris in, as it flies out into space and then twinkles out.
- The beginning of the episode shows Vanilla stopping by the Chaotix Detective Office to thank the Chaotix for all that they did for her and Cream. Amy and Cream then bring a whole bunch of snacks to Tails to try and cheer him up which all of this is cut from the English dub.
- In the Japanese version when Sonic is next to a tree he was talking to Dark Oak, but in the English version he was talking to Cosmo instead.
- Shown only in the Japanese version, Shadow is seen to be alive, putting a rose on Molly's grave.
- Eggman commenting on Rouge's breasts.
- In the scene where Tails is crying to Sonic, the Japanese version has Tails blame Sonic for not being able to save Cosmo. In the dub, Tails doesn't. In the same scene, the dub has Tails lightly sob. But in the Japanese version, Tails screams and bawls when he fell into Sonic.
- Most of the scene with Super Sonic and Super Shadow has the color of space changed. In the Japanese version, it is just plain black, but in the French version, it is a vibrant blue and white color with what seem to be trees, (the same background that Lucas and Earthia are seen in).
- The transporter of Eggman that Chris used to go home in is called "Hurry and Go Home Version 1". In the English dub, it does not have any name.
Title in other languages
|Japanese||星の生まれるところ||The Place Where Stars Are Born|
|French||La renaissance des planètes||The revival of the planets|
|German||Leb wohl, Sonic!||Farewell, Sonic!|
|Italian||Ritorno a casa||Returning home|
|Spanish||Donde nace un planeta||On the Planet he was born|
- When Sonic says "Good night, have sweet dreams!" after he runs, Dark Oak starts to laugh.