In the Thrawn novels, there’s something of a sub-plot about Talon Karrde putting together an alliance of smugglers to oppose the Empire.  Mazzic is one of those smugglers, but not much time is spent describing him.  For the comics, someone decided, hey, this is Star Wars, they might as well make him an alien.  And so we have Mazzic the blue Myke. 

Wookieepedia uses the words “famous” and “legendary” to describe Mazzic, but those seem to be overshooting him a bit.  He’s a visually interesting alien that has some significance to the plot.  The comic artists seem to have done him a favor in this regard.  His alien appearance and his unique cross-draw chest holsters would be his main appeal as an action figure.