Hello, I am a long time fan of the Sonic games, as well as the Sat AM series and comic series. Back between 1993 - 1997 I used to draw Sonic characters a lot. I did my own written stories with my own freedom fighters and Mobians interacting with the main cast. I thought I'd post some of them just for fun.

Meadow - A female reindeer with martial arts skills.
Rick "Mask" Skyer - A raccoon that specialized in espionage.
Tito - A chinchilla and boyfriend of Meadow.
Sasha - A shy red squirrel with a secret crush on Sonic. She gathered intelligence.
Tasha - Sasha's twin sister. She got roboticized.
Sebrina - A smilodon that was Rotor's love interest. She too became roboticized.
Lance - A stallion. he was a veteran freedom fighter that became roboticized.
Kit E. Hawk - A veteran freedom fighter whose right arm became roboticized.
Wolfgang - A young wolf that was a friend of Tails.
Pupi - The youngest of the bunch at four years old. He was a refugee bushdog from a jungle tribe. He used a bungee-type rope as a too and for defense.
Brat - A streetsmart bat. She is a little older than Tails.
Katara-su  - Future daughter of knuckles. Seriously, I made up her name years before 'The Last Airbender'. I created her around mid '97, before I heard of Lara-su. 
Nitro - Vector's son.
Spectra - Espio's daughter.
Rocky - Mighty's son.
Aristotle - Son of Archimedes the fire ant. His task was to train Katara.
Tera-li - A Dark Legionnaire. She was a blue echidna with a cybernetic arm.
Lt. Kari-me - A sarcastic, coffee-chugging EST officer.
Lupe & Maria - Tito's chinchilla sisters.
Rose - A pink hedgehog from an abusive family.
Stealth - A hedgehog that became 80% robiticized. Only half of his face and his quills remained organic.
Lily Prower - Tails' older sister. Their parents died in a plane crash over an Egyptian-like region. She was raised by a pharaoh that guarded a series of emeralds dubbed "Rainbow Emeralds" due to their constantly changing colors. Lily could rival Sonic's speeds, but in flight only.
Pharaoh Neferu - A long-eared desert hedgehog with sorceror-like powers. He is immortal and shared a connection with the rainbow emeralds. His son, Menkure was murdered.
Khufu - An andro sphinx and Neferu's bodyguard.
Andromeda - Khufu's mate. She is a northern gyno sphinx.
Nargetherek - A manticore and arch nemesis of Khufu. Manticores were sphinxes that allied with an evil demon sorceror and became transformed under his influence.
Nakros - Sorceror demon from the Realm of the dead. He took control of Robotropolis from Robotnik.
Fujiko - A three-tailed fox. I only drew a few images of her, but never developed a story.   
Juice - Sonic's future son (based on Manik before he was named). He renounced being the future king in order to train as a monk.
Alicia - Inspired by Sonic before she was named. She took control of the monarchy, but became a corrupt ruler.
Akira - A leopard from an aikido school that knew Bunnie.
Xiong Mao - A female panda with a fiery temper.
Aikido - A red panda that teased Xiong Mao.