User blog comment:HalointheSkye/Volume 3 Chapter 10 - Battle of Beacon (IN WHICH DRAGON SH*T TURNS INTO GRIMM)/@comment-24994749-20160202003804/@comment-24994749-20160202132903

Miles said that a while back, though. It could be the Dragon.

There are surely more of them, but this one was somewhere around Vale and that's where we know Summer wwnt on missions.