|Character Type||Playable Character
|Affiliation||Mushroom Kingdom Coalition
|Original Appearance||Sonic the Hedgehog (1991)
"An adventure's no fun if it's too easy."
Sonic the Hedgehog (also known as just Sonic) is a playable character in Mushroom Kingdom Fusion and member of the Mushroom Kingdom Coalition. Known as The Blue Blur, Sonic is the fastest character in the game. His sidekick and best friend is Miles "Tails" Prower.
Sonic first began his role in the original Sonic the Hedgehog, where he took it upon himself to stop Dr. Eggman's attempts to use animals as an energy source and acquire the Chaos Emeralds. Ever since then, Sonic has spent time and again foiling his plots to establish the Eggman Empire, as well as many other threats to the world. Along the way, he acquired many friends and allies, such as Tails, Knuckles, Amy Rose and Blaze the Cat, and traveled to many exotic locations, including alternate dimensions, all over the world and even places, such as the Arabian Nights and Camelot.
Sonic carries most of his abilities from Sonic the Hedgehog 3 and from later games.
- Sonic can perform a rolling attack when ducking or running, allowing him to defeat enemies quickly. His curled-up form can be used to break bricks and activate ? blocks.
- Sonic has his spin dash by holding down and tapping run. This can be used to gain a longer aerial jump.
- Sonic has a ground pound/jump cancel attack (similar to the "stomp" from recent Sonic games) and his duck is projectile-resistant.
- Sonic has the ability to perform Insta-Shield from Sonic the Hedgehog 3.
- Sonic has enhanced traction, allowing him to come to a stop faster than the Mario Bros. even at his superior top speed.
- Sonic is the fastest player in the game. Due to his high top speed he also has the second best long jump (behind Luigi).
- Sonic can't swim naturally, so he needs a lifejacket in order to swim. Lifejackets will be found in all levels that require swimming, but not for areas with water that Sonic can navigate normally. Sonic cannot drown like all the other characters and unlike those in the original Sonic series. Sonic can also bounce off water surfaces if he's at running speed.
- Sonic uses a ring-based system from his games, in which he loses all his coins when he takes damage and will die if struck without any. He can reacquire dropped coins for a short time after being hit. One negative to Sonic is that whenever he takes damage, there is a knockback effect which can become quite irritable at some points.
|10 Rings||Coin Refill||Sonic will gain 10 rings/coins. If Sonic has at least 10 rings/coins, then a second-tier powerup will be given.|
|Fire Shield||Fire Shield Sonic||Sonic will gain a shield like in Sonic 3 & Knuckles and Sonic 3D Blast. It is resistant to fire-based projectiles, and he can even produce a fire dash ability in mid-air, helping him cross some long gaps.|
|Raccoon Leaf||Rocket Boots Sonic||Sonic will gain rocket boots in order to fly. His rocket boots come from Sonic Triple Trouble.|
|Tanooki Suit||Mark II Rocket Boots Sonic||Sonic will gain the Mark II rocket boots. This allows for greater flight abilities and Sonic gains a magnetic shield to attract coins.|
|Bubble Shield||Bubble Shield Sonic||Sonic will gain the Bubble Shield, which reflects most projectiles, like the Fire Shield. It will also help Sonic to bounce to reach a higher place.|
|Spartan Shield||Energy Shield Sonic||Sonic will not gain Halo armor of any kind, but he will instead gain a force field. It has a regenerating shield, like Mario's Spartan suit. It also has magnetic properties to attract coins and rupees.|
|Quick Man Suit||Quick Man Sonic||Sonic loses the momentum penalties he normally has in any other form, as well as zero knock-back from attacks. He is also able to use Quick Boomerangs as a ranged attack. This is Sonic's only power-up form that gives him projectiles.|
- If the player clears a level & grabs a Starman as Sonic, the "Level Complete" & "Invincibility" music from both "Sonic the Hedgehog 3" and "Sonic & Knuckles" play.
- If Sonic loses a life, the "Lose a Life" music from Sonic the Hedgehog (1991) on the Game Gear/Master System plays.
- The 1up sound effect from the Sonic games on the Sega Master System plays whenever Sonic collects a 1up. Originally, the sound effect that played was the 1up sound effect from Sonic & Knuckles on the Sega Genesis but was changed due to the length being too long.
- When playing as Sonic, the "PLAYER START!" screen before a level starts comes from Sonic The Hedgehog 3 and Sonic & Knuckles.
|Main: Mario | Luigi | Sonic | Tails | Wario | Waluigi | Arthur | Roll | Link | Simon Belmont|
|Secret: Vile | Classic Mario | Classic Luigi | Proto Man | Mega Man | Zero|