Who is that dragon? Revisited

There's one really big question I somehow skipped over in my previous post about the dragon on the deluxe edition of DH. How did the trio get the dragon to cooperate?

So, perhaps you really can't tame a dragon... but maybe you can magically control one, anyway.

Being a Parceltongue might be one step in the right direction, but if you put dragon's blood into the equation...? Dunno.

Another thought had come to mind while reading a thread on Galadriel Waters' New Clues 6 Discussion forum. Harry and the other TWT champions received animated models of the dragons they had to get the golden egg from. I know that Harry battled a Hungarian Horntail, which looks nothing like the dragon pictured in the Deluxe artwork, and the other champions also battled dragons that don't match the artwork, but where did the TWT organizers get those models? Might there be one for the Antipodean Opaleye, or perhaps for another dragon that might match this one? If so (and I should think so), then he might be able to get one of these models and use an Engorgement charm (or Hermione could). Then they might be able to control it.