During STC's lifetime it spawned a small
collection of special edition issues that were produced at
random times in the year. One of these featured the first
appearance of Knuckles.
The first and most
commonly known are the Summer Specials these were purely
Sonic Comics unlike normal comics and contained an
assortment of different extra content such as competitions,
and games to play. As far as I know these where produced in
1994, 1995, 1996, and 1999 (The Summer Special of '99 was
also only reprints).
edition comic that is commonly known about but quite rare to
actually own is the Knuckles Knock Out Special which was
released in the summer of '96 it was very much like the
Summer Specials but was completely Knuckles orientated.
There was only one issue of this made.
There was only one
other non-sonic full special edition issue and that came in
the form of the Eternal Champions Special Edition. It was
produce around the time of the Mega CD apparently to boost
sales and contained comics strips, character stats,
competitions among other things.
The last set of
special edition comics are the Poster Mags these where
normal sized issues that folded out to reveal an A1 poster,
the content of these varied widely; anything from game
walkthroughs to 6 page comic strip additions to the regular
editions (Streets of Rage and Shinobi). The poster Mags
where produced from late 1993 - late 95.