Sonic X (TV)

Yuji Naka, father of Sonic the Hedgehog, had personal involvement with Sonic X. He was pleased with how the anime turned out.

Episode 26, "The Birth of Super Sonic" had different ending visuals, because it was a special episode.

You might have noticed a lot more from the characters in this anime than in the games. The writers for Sonic X were given more freedom to develop the characters' personalities, because most things are obscure in the games. Such examples are Sonic showing his love for Amy, the way Sonic can be lazy, Eggman's more humorous side, and so on.

The Final episode, on the DVD ver. had the songs by OFF COURSE removed, and replaced by Hikari no Michi and Last Story(From Sonic Adventure 2).

The pilot episode of Sonic X (originally simply known as SONIC) had the future of the anime heading in a completely different direction. Minor characters, such as Big the Cat and Danny appeared to have much larger roles than the ones depicted in the current version. Apparently Shadow was originally going to be in a role that was in no way related to his connection with SONIC Adventure 2 whatsoever, as could be seen near the ending of the pilot episode when he unleashes his towering machine against a willful Sonic. The X-Tornado was slightly modeled after the original Tornado 1 (which can only be sighted in the anime during episode 18), namely with colour scheme. Lastly, but definitely far from being the most overlooked feature of the pilot, a mysterious hedgehog (dubbed as Nazo by most Sonic fans) flashes shortly on the screen for a few seconds before the episode ends. Theories of whom this character is include a fusion between Sonic and Shadow, the prototype version of Super Sonic, and even a revamp of Hyper Sonic from the original video game series, and arguments have often constantly broken over this.

Sonic X series 2 (53 to 78, referred to as season 3 in English-speaking countries) was originally released for international airing, although Japanese voices have already been recorded as original masters.

Ryan Drummond, the official voice actor of Sonic in the English language versions of the Sonic the Hedgehog video games (pre-Shadow the Hedgehog), wanted to provide Sonic's voice for 4Kids's English adaptation of Sonic X. However, 4Kids rejected him simply because he did not reside in New York, where the production studio is located. Even though he offered to move to New York just for the mere chance of trying out for the role, 4Kids refused to accept him. This decision had upsetted many Sonic fans.

Before the Japanese trailer was released at the World Hobby Fair (January 2003), there was already a three-minute teaser existing that was created sometime during early 2002, as the collaboration preview between SONICTEAM and TMS Entertainment. Cream the Rabbit was stated as a new character (due to the trailer being released before her video game debut, Sonic Advance 2, was completed) and Cheese is plainly referred to as "CHAO." This trailer was narrated in English, probably done most to market in some TV network sales pitching. Scenes from the two trailers have been used for the anime's first opening.

many of the story arcs come from the sonic games and follow them closely , almost to a tee. the chaos arc was from sonic adventure 1, the only difference is cream was not in the game, and the shadow arc was from sonic adventure 2, again cream was not in the game nor was team chaotix, who was never really in any sonic game besides sonic heroes which they never did a episode arc of, however team chaotix was in the sonic comic series and were first introduced in a side series featuring knuckles as the protagonist. 

For unknown reasons, Episodes 53 through 78 have never been released in Japan in any format. Despite this, a full Japanese audio track was recorded for these episodes and released legally in Taiwan in a VCD set containing these episodes. Currently, this is the only legal way to buy these episodes with Japanese audio. 

Goof: In episode 1, Eggman's base was erroneously referred to as "Chaos Control" in the English dub. This may be due to a scriptwriting error, or the fact that the 4Kids Entertainment producers knew nothing about the Sonic the Hedgehog video game series at that time or a combination of both.

In episode 1, there is mentioning that one of the Speed Team members gave Sam Speed "something extra" in his drink without people noticing. This may be a reference to Sam using performance enhancing drugs. This mentioning was excluded from the English dub.

In episode 1, marks the only time in which Rouge makes an appearance, but her theme music wasn’t being played.

In episode 1, two civilians that resemble Lupin III and Fujiko Mine from the Lupin III franchise can be seen in one of the crowd scenes when Sonic first arrives in Station Square.

In episode 2, for the English dub, the flashback of the ending of the previous episode was excluded in the beginning.

In episode 2, in the Japanese version, when the lasers appear on top of the cameras, Sonic swears in English. He however doesn’t swear in both the English and French dubs.

In episode 2, when Chris scolds at Sonic for being reckless in the original, he warns about a war Sonic could have started. For the English dub, he just scolded him about how they could be risked getting arrested by the military.

In Episode 8, Eggman's "E-90" mecha is modelled on "Thunderbird 2" from the 1960's show "Thunderbirds", complete with the giant "pod" that can be ejected from it's body.

In Episode 11, the SWAT team Rogue guided into Eggman's fortress were armed with Automatic Rifles which resemble the MP5 Series. In Episode 12 to 13, the SWAT team were armed with rifles which resemble the SIG 552 instead, perhaps because the SIG series uses higher calibre bullets (in other words, bullets which have more armour damaging potential but are louder when shot) which are better for assault operations when not much "Sneaking" is involved after infiltration.

In Episode 13, the giant Robot called E-18 "Guerra-Hard" is a complete spoof of the Super Robot "Mazinger Z". Even Eggman's Egg Mobile docks into the head in the same fashion the "Hover Pilder" does to Mazinger Z! However, the robot was only capable of physical attacks (i.e. Punches and Kicks). Nope, no Rocket Punches, no Missiles, no "Breast Fire".

In episode 17, marks the first episode to not feature Sonic.

In Episode 20, The short-lived Egg Fort II bears a resemblance to Star Trek's "Enterprise".

In episode 39, the English dub edits out the cigar that Vector was holding in his hand during the scene where he impersonates Columbo.