Sonic the Hedgehog is a video game character. He is a 15-year old blue hedgehog who can run at the speed of sound. By curling into a ball and spinning quickly, he can do a helpful "Spin Attack" which he uses to defeat the villains and save the day. He has been in many games made by the company Sega, but also in television series, books and comics (published in America by Archie Comics). He has many friends, including Miles "Tails" Prower, a two-tailed fox that can fly by spinning his tails very quickly or Knuckles the Echidna (who is strong, and has been in Sonic games since Sonic the Hedgehog 3). With them, he fights against his arch nemesis Doctor Eggman, an evil scientist attempting to conquer the world.

Sonic's appearances

In games
Sonic is the mascot of Sega, which created it in the early 1990s. At first, Sega wanted Doctor Eggman to be their mascot, and a good guy. But, the people in Sega liked the new idea of making a blue hedgehog as the mascot. Doctor Eggman settled as the bad guy instead. Sonic’s franchise has grown, and more characters are displayed in games.

Here is a list of some games Sonic is in:
 Sonic the Hedgehog
 Sonic the Hedgehog CD
 Sonic the Hedgehog 2
 Sonic the Hedgehog 3
 Sonic & Knuckles
Sonic X-treme (cancelled game)
Sonic 3D Blast
 Sonic R
 Sonic Adventure
 Sonic Adventure DX
 Sonic Battle
 Sonic Adventure 2
 Sonic Adventure 2 Battle
 Sonic Advance
 Sonic Advance 2
 Sonic Advance 3
 Sonic Heroes
 Shadow the Hedgehog (Game)
 Sonic Rivals
 Sonic the Hedgehog (2006)
 Sonic and the Secret Rings
 Sonic and the Black Knight
 Sonic Unleashed
 Sonic and Sega All-Stars Racing
 Mario & Sonic At The Winter Olympic Games
 Sonic Generations
 Mario & Sonic At The London 2012 Olympic Games
 Sonic Boom: Fire and Ice
 Sonic Boom: Rise of Lyric
 Sonic Boom: Shattered Crystal
 Sonic All-Stars Racing Transformed
 Sonic Lost World
 Sonic Mania
 Sonic Forces

In cartoons
He appeared in his own made-for-video movie in 1999.
In most of the cartoons from the 1990s his voice was provided by Jaleel White (who was best known at the time for his role as Steve Urkel on the television show "Family Matters") and in later cartoons his voice was provided by Jason Griffith. Sonic also stars in his latest cartoon from Japan. It is called Sonic X, although Sonic X has ended.

Here is a list of cartoons Sonic is in:
 The Adventures of Sonic the Hedgehog
 Sonic the Hedgehog (SatAM)
 Sonic Underground
 Sonic the Hedgehog (movie)
Sonic X
Sonic Boom

In comic books
Archie Comics in America has been making comics with Sonic as the main character. He is also shown with famous characters like Knuckles and Tails, but with also a few new ones. Some of the characters are not in any Sonic games, but some are in a very old cartoon, Sonic the Hedgehog SatAM, made by DiC in 1993.

Other characters

Friends
 Miles "Tails" Prower: Tails is an eight year old fox. He has two tails that he can spin like a propeller, allowing him to fly. He has been a friend to Sonic for a long time. He also sees him as a mentor, someone who trains him and treats him as a brother. He is also very skilled with machinery (mainly aircraft.) He was first shown in the video game Sonic the Hedgehog 2. He can also turn Super using the Super Emerald,which Sonic and Knuckles uses to turn Hyper.
 Personality: Tails is a very friendly and humble fox. Though he lacks confidence, he is always quite capable around Sonic and often helps him out. For a long time Tails seemed happy with just being a sidekick, but in Sonic Adventure he wanted to be more independent. Tails has a few weaknesses; he lacks confidence, is very afraid of lightning and ghosts, and also he has a tendency to talk too much, which causes him to accidentally blab out secrets or plans lots of times.
 Amy Rose: Amy is a tomboyish 12 year old pink hedgehog. She is in love with Sonic and she wants to marry him, but so far, Sonic has not accepted this offer. She has a large Piko-Piko hammer for fighting with bad guys. She was first shown in Sonic CD.
 Personality: Amy was once presented as being kind and sweet (and slightly naive.) In more recent games she has become more violent and aggressive. However, she is extremely protective of her friends, and if a bad guy tries to hurt them, she will use all her skill to defeat the bad guy. Despite her violent tendencies, Amy has a very good heart, she never gives up, and she is the most optimistic and cheery character of the franchise. She really cares about her friends, and helps them reach their goals.
Traditionally she wore a  green shirt and a orange skirt. This changed to a red dress in sonic adventure.
 Knuckles the Echidna: Knuckles is a 16 year old echidna. He may be the strongest of all of the characters and has two sharp claws on each fist he uses to fight with bad guys. Most of the time, he takes care of a very special gemstone called the Master Emerald on Angel Island, a floating island in the sky. He was first shown in the video game Sonic the Hedgehog 3. He can also turn Super using the Chaos Emeralds, and Hyper using the Super Emeralds, which Sonic also uses to turn Hyper.
 Personality: In the games, Knuckles is independent, headstrong, devoted to his duty and is very trusting (this leads to him being tricked by Eggman a lot). He is very serious and usually likes to be by himself, but can be relied upon to help out whenever the planet is in danger. Knuckles is extremely stubborn and is often described as a loner. Because of his flaws, he and Sonic do not always get along, but are still allies.
 Cream the Rabbit: Cream is a 6 year old rabbit who can fly with her ears. She also has a friend, a baby chao named Cheese. She was first shown in Sonic Advance 2 for Game Boy Advance. She is a very close friend to Amy.
 Personality: Cream is polite, follows manners, and does what she is told. She is very friendly. She is brave as well, usually not afraid to go out on an adventure. However, she is a bit naive. Cream spends most of her time outdoors. There, she likes to play with her friends, or collect flowers. She loves adventures and exploring. Indoors, she likes watching TV. Her favorite food is ice cream. She does not like violence. However, she will fight to protect the people she cares about.
 Shadow the Hedgehog: Shadow is a cloned hedgehog with super speed like Sonic's. He is actually immortal due to scientific experimentation, but he has the appearance of a 15 year old hedgehog. He is also known as Project Shadow and "The Ultimate Life Form". He is often mistaken for Sonic, although they have some differences between them. Shadow has red and black quills and they are more spiky then Sonic's (resembling Sonic's super form). Shadow was created by Dr Gerald Robotnik (Dr Eggman's grandfather), for the intent of creating peace on earth, on the Space Colony ARK. His creation, however, was enabled by the blood of Black Doom, the leader of an alien race called the Black Arms. His goals were different than Dr Gerald, as he wanted Shadow to collect the Chaos Emeralds for him so the Black Arms could rule Earth. After his creation, Shadow spent some time with Maria (Gerald's granddaughter and Shadow's first friend) who taught him about humanity, true friendship and how to be kind to others. But the G.U.N. (Guardian Units of Nations) thought he would be a threat to humanity. As a result, they eliminated everything related to the project, including the staff and Maria, who was in the process of saving Shadow. He was sent from the ARK in an escape capsule, but was captured by G.U.N. and was kept frozen (like Fry from Futurama) at their base at Prison Island. The death of Maria made Dr Gerald go mad, altering Shadow's memory while he was still frozen to manipulate him into trying to destroy Earth. With help from Sonic and his friends, he was able to regain his memory and his purpose to save the earth, and stopped Dr Gerald's plan to crash the ARK into the planet. This led to Shadow falling from space and getting amnesia, only remembering Maria's death. He went to find his memory, which lead to him defeating Black Doom and the Black Arms. He has made a commitment to live his life without the burden of his past. He took an offer from the present Commander of G.U.N. to work with them as an agent, but he still works on his own terms. Shadow has unique abilities to use the Chaos Emeralds in ways Sonic and friends have never shown to be able to. One of these is Chaos Control, the ability to warp and manipulate Time and Space with a Chaos Emerald's power. Shadow's first appearance was in 'Sonic Adventure 2'.
 Personality: Shadow is of Sonic's most pronounced rivals, but at the same time, is one of his friends. Originally an enemy, he is more like an antihero nowadays. Shadow's personality is very different from Sonic's, being very serious and somewhat cocky. He originally had an obsession for finding out the truth about his past, but now since he has found it, he is willing to live a normal life...as normal a life can be for Shadow, that is.He can also turn Super using the Emerald.
  Rouge the Bat: Rouge is a female majestic bat. She works for the Government Agency called G.U.N. Her hobbies include treasure-hunting and collect rare gems, including the Chaos Emeralds. Her powers include flying with her wings and doing powerful kicks with her feet. She is often with Shadow (being his only true "friend") and likes to "tease" Knuckles (Sonic X makes this out to me more of a romantic relationship than the games do.) Rouge's first appearance was in 'Sonic Adventure 2'
 Personality: Rouge was originally self-centered, but over time, she has learned to show concern for others (especially her friends Shadow and E-123 Omega, one of Eggman's robots who rebelled). She is not above using her looks to get what she wants.
 Cosmo: Cosmo is a female child of a plant-like alien species whose homeworld was destroyed by the villainous Metarex. She is an friend of Sonic the Hedgehog and his friends, and many see that her primary purpose in the series is that of a love interest for Tails. This is because the two characters are of the same age for one another. She is only in Sonic X.

Enemies
 Doctor Eggman: Doctor Eggman is a smart scientist. He likes to make an army of robots to take over the world, but Sonic and his friends always keep making him fail. He was first shown in Sonic the Hedgehog. In early U.S. releases of the games, he was called Doctor Robotnik. He is called Doctor Eggman because his body is shaped like an egg.
 Eggman Nega: Eggman Nega is one of Dr Eggman's relatives from the future. (He first appeared in Sonic Rush) There is some confusion as to whether he is from a different Dimension (as stated in the Sonic Rush series) or from the future (stated in Sonic Rivals)

Transformations
 Super Sonic is actually Sonic himself. As Super Sonic, Sonic is faster and stronger, and he is gold in color. He becomes Super Sonic only if he finds all seven Chaos Emeralds and, in the old games, gets 50 gold rings. He was first shown in Sonic the Hedgehog 2. Many other characters have a Super form. For example, Knuckles can become Super Knuckles.
 Hyper Sonic: Hyper is like Super Sonic, but he is even more powerful. His color is always changing. Hyper Sonic was in Sonic the Hedgehog 3 and Knuckles and was not in any other Sonic the Hedgehog games. Super Sonic becomes Hyper Sonic if he finds the 7 Super Emeralds and fifty gold rings and then double jumps.

Items
 Chaos Emeralds: The Chaos Emeralds are 7 stones that have been around for a very long time. There is very powerful energy in them that has both evil and good power. As a result, both good guys and bad guys are constantly looking for them. Sometimes, characters can transform by using their energy. For example, Sonic becomes Super Sonic.
 Super Emeralds: The Super Emeralds are present only in Sonic 3 & Knuckles. These are even more powerful than the Chaos Emeralds. When Sonic collects them all, he can become Hyper Sonic.
 Master Emerald: The Master Emerald is a very special green gem that is much larger than the Chaos Emeralds. It holds a great power that can even control the Chaos Emeralds. It is on Angel Island, the floating island where Knuckles lives. Knuckles guards and protects the gem. He is also one of the only people able to control its power.
 Rings: Also called "power rings" or "magic rings", these are golden rings which contain a special power. In the games, Sonic will die if he is attacked without rings, but with more rings, he can survive.
 Monitors: These items are seen across levels. They give power-ups when opened, such as shields, rings, or extra lives. But some can hurt you.

Voice actors
Throughout the years, Sonic has went through several different voice actors. Jaleel White began voicing the character in the DiC animated series Adventures of Sonic the Hedgehog, as well as Sonic SatAM and Sonic Underground. White also reprised the role again in the 2013 Sonic fan film.

Beginning in 1998, Sonic was voiced by Ryan Drummond, starting with Sonic Adventure.  He continued to voice the character for six more years until 2004, his final performance as Sonic was in Sonic Advance 3. Drummond was replaced by Jason Griffith starting with the anime series, Sonic X, with Griffith voicing Sonic within the games starting with Shadow The Hedgehog in 2005, he voiced the character for four more years until 2009 in Sonic and the Black Knight. However, his recycled dialogue as Sonic was used in Sonic & SEGA All-Stars Racing. After his departure from the role in 2010, Griffith did continue to voice Sonic in various 4Kids promotions until September 2014, when the Vortexx program came to an end.

Griffith was replaced by Roger Craig Smith, starting with Sonic Free Riders and Sonic Colors. Smith announced on his Twitter account on January 29, 2021, that he would no longer voice Sonic, with his departure confirmed by Sega the same day. On May 26, 2021, Smith announced that he will continue to voice Sonic once again. Ben Schwartz voiced Sonic in the 2020 feature film, and will reprise his role for the 2022 sequel.

References

Other websites 

 American website
 European website
 Sonic Channel
 Google English translation of Sonic Channel

Mascots
Fictional animals
Fictional characters introduced in 1991
Sonic the Hedgehog characters
Video game characters in movies