Rift Quest:Drakes in the Draft  

On the ground floor of one of the towers at Temple of Marakris is a Teleport Urn that will take you to the roof. Here you will find four catapults and see some drakes circling the tower. It may take a few shots to get the timing down, but look for the sparkle in the air. That is where the catapult load will meet the drake if you get it right.

Oh, and, you're on your own for getting down. Hope you can fly... the trick is to throw yourself at the ground and miss.