Well, I love the idea of the baby dragon type of things, but I think it is time for another!
Would it not feel more real and exciting if one of the main elder dragons flew around the whole of Tyria and landed in random exotic locations?
If the dragon was to land in a low level area, then it would automatically fit to the locations level, which would mean more people would be able to join in with the fun. The dragon should not be easy to kill like Shatterer or Tequatl but should be more interesting, like the dragon gets injured very badly then flies to another location.
There should be fire falling down as it is injured and is flying to the next location that it is going to land. As there would be a lot of damage to the ground, players should help out the nearby villagers and fix broken pieces of wood, splash water on homes that are on fire and slay the dragons minions that threat the towns people. After the dragon has left one spot there should be a chest. The dragon should be untraceable, therefore who ever is in the location that it lands next should face it on his/her own. If the person cannot and the dragon has been there for ages then the dragon will fly off again to a completely random location!
This marathon across Tyria, if you would like, would get the community more involved with each other because everyone will be looking for the next location. The chest if the dragon gets slain should hold exotics and precursors! It would be even more cool if you (Anet) put in the chest, Pet dragons which will be extremely rare that can help people fight Npcs and not PVP.
Things I missed out or restating:
The dragon should be on a 2-4 hour spawn window and would need to land 3 times for it to be slain.
All chests are normal (like the other baby dragons) except last chest
Anyone can fight it within the area ( not only level 80s)
first encounter more likely to be in a low leveled area , last chest is only in a level 80 area
Pre event before it lands and after event for when it flies off
last encounter, chest more valuable than the rest
There should be clues to where it is or where it is heading next like a treasure trail(could be something to do with the weather, how strong the wind is or the direction the wind is travelling)