I saw this post and thought it was odd because I don't remember Gullerback ever summoning me on live. He was a pain in the ass to solo on my wizard because I couldn't ever snare him and had to spend all damn day getting ahead of him between nukes, but I honestly don't remember him summoning. None of the comments
here on Allakhazam refer to him summoning, and the only references to summoning are of the "if he summons, it never happened to me" variety, despite the fact that the Allakhazam database itself seems to believe that he does.
I don't know for certain one way or the other, but it seems like it's something that
might be wrong and I'm wondering if anyone has any more concrete evidence one way or the other.