I'm kind of disappointed by my luck.
I was in Dragon Cave yesterday (at least, I think it was yesterday) and I just so happened to go into the Alpine region, and lo and behold, it was an egg "covered in icicles," which happened to be the Legendary Ice Dragon.
Of course... knowing me, I just so happened to have clicked to move to the coastal region before I noticed.
I went back as fast as I could, but when I did the egg was already stolen.
Today I happened to have come across another rare egg, and I happened to have done the same exact thing, motion for motion...
...
Darnit.