One day your friend send a package to you by Wyvern Post, and many days left you still not receive the package, these may happened on your package:

1)Missing
Just fall down to nowhere, they usually didn't hold the package tightly.

2)Crashed
When they were trying to land, if they did a bad landing, your package may be crashed by their feet. Although most of the postman are medium size dragon, it is enough to crash the package.
...or they just want to jump on it.

3)Sanding to wrong person
Well, they normally don't check the address carefully. Sometimes they even remember the wrong address.

4)Sky soccer
Playing the soccer as usual, but the ball is your package.

Aurora Chronicle