Mystical Ninja, formerly known as BioHedgehog, BioHedgie, AmyFan2K3, and Golden Sonic, is a Sonic community scener from 2003-present. He is probably best known for the multiple accounts he's had over at the Sonic CulT forums and Sonic Classic back in 2003, as well as the many aliases he's had over the years.
Mystical Ninja has been lurking around the Sonic scene since 2001, when he was thirteen years old and first dug out his Sega Genesis and his copies of Sonic 1 and Sonic 2 after not playing them in at least four years (or more). During a random Google search for Sonic the Hedgehog-related sites, he eventually came across Area 51. He soon came across various other Sonic secrets-related sites as well, such as SSRG, SWS2B, Sonic CulT, etc. However, he never actually bothered to join any message boards until two years later, on February 1, 2003, which by coincidence, is the day after the original SSRG was shut down.
The first Sonic message board (as well as the first message board he's ever registered at, period) he registered at was the Sonic CulT forums, and went under the name of "BioHedgehog". He was just your average poster, and was hardly considered a "n00b", other than the fact that he had a strange habit of halting words in his posts with elipses, or sometimes using more exclamation points than necessary. However, he was still generally disliked by some people, due to the fact that he would often befriend and come to the defense of certain members whom others considered to be idiots whenever someone flamed or made a request for them to be banned. BioHedgehog was also disliked, because of the fact that he annoyed people with the multiple accounts he's had (BioHedgehog, BioHedgie, Mystical Ninja, AmyFan2K3, etc.) After the original Sonic CulT forum somehow got wiped out in August 2003, BioHedgehog reregistered as "Golden Sonic". He continued posting and was an active member for a while, until he was eventually banned on June 30, 2004, because they were "tired of [his] stupidity". He attempted bandodging under the name of "SuperGoku14", but was quickly found out and IP banned. However, that wasn't the end of him, because he bandodged yet again, while under the name of "Krazy Monkey", where he was able to continue posting while no one suspected a thing. Very few people knew who he was while under this alias.
On April 5, 2003, Mystical Ninja registered at Sonic Classic under the name of BioHedgehog once again, and also decided to bring his alternate accounts with him. Mystical Ninja was a regular poster over at this forum as well, and wasn't quite as disliked as he was at the Sonic CulT forums (although, some people did still find him irritating because of his muliple accounts). On September 13, 2003, Mystical Ninja registered a joke account and impersonated Sonic Chaotix, which eventually led into getting himself IP banned by ronchie02. However, he was unbanned a few days later after having an AIM conversation with Sonic McTails. The very next month, he registered another joke account by the name of "SSJ_Kakarot_643", which was meant to imitate n00bs who type with blatant grammatical errors, and would frequently post a bunch of nonsense in the Trash Talk forum. Eventually, many people got fed up with all his alternate accounts, and Mystical Ninja requested to have all of his alternate accounts deleted. After that, he just continued posting regularly with his normal account until the end of SSonicNet's lifespan.
Mystical Ninja registered at SWS2B on April 21, 2003, this time under the name of Mystical Ninja, rather than BioHedgehog. Unlike the last two forums, he didn't bother registering any alternate accounts here (until many months later), and for the most part, stuck with one account. Mystical Ninja's been around ever since the board was being powered by phbBB, and witnessed it getting converted to Invision Power Board a few months later. Unlike the previous two forums above, Mystical Ninja never ended up getting himself banned from here, and continues to post even up to this day (and even ended up getting promoted to Oldbie status). However, he isn't quite as active as he used to be.
Although he wasn't around during the lifespan of the original Area 51 board, he was, however, present when the new one was created in 2003. From there, he registered the name of "AmyFan2K3", and earned himself a reputation as a spammer. There was a long-running spam thread that he frequently posted in, which probably had at least 200 pages.