Apparently all of my breeding hints are unlocked, even the ones I never unlocked, so I have hints for the newbies. Actually, they're all the same.

It states:

The breeding pair of dragons must contain the antarian/arcturian/bizurian/polarian/sorarian dragon and either a galaxy dragon or an epic dragon.

So if you're trying for an Antarian, for example, you'd need Antarian+Epic or other Galaxy.

I just wish the sandbox would update so I can see what all the possible outcomes of these pairings is. Waiting is frustrating.