Lets discuss about Mighty here. Some believe he is a prototype of Sonic sonce both Hedgehogs and Armadillos can roll in to balls. He made his 1st appearance n the game SegaSonic the Hedgehog.

Personally, I've never really liked Mighty. I always thought of him as a Sonic recolour and an un-original character. In fact, I highly doubt he's even official. Bean and Bark are owned by another company so could this be the same in Mighty's case? I think so. Sega aren't allowed to use Mighty anymore because the company that owns him have prevented it. I cannot give any explanation as to why he keeps appearing in the comics though. Maybe they gave the permit to Archie instead of Sega? Another theory I have is that the company was so inspired by Sonic, They created Mighty and asked Sega to include him in a few games. The games he appeared in gained a poor reception, So they stopped Sega from putting him in the games.

Hhm , I heard that someone from SEGA left and took Mightys copyrights with him .
He could have been a good character in Sonic Heroes though .
I personally think's hes okay .

Not sure about that. If that was the case, SEGA would not be allowed to show pictures of Mighty in Sonic Gems Collection. And, seeing as Archie Comics are Sega-of-America licensed, I doubt that's the case with Archie either.

I personally enjoyed Mighty being along with the Chaotix crew, but y'know, it didn't make too much of an impact on me when he was removed.