[Crayder]

I think it would be better in a rc baron. Or, you could do speed levels. Like if the goblin is flying fast enough create a baron in the same spot at the same angle and velocity and put the player inside. When it slows do the same but use a goblin... It wont look perfect but the concept is better.

Still, the effort was enough to earn some rep. :P

Also instead of AttachObjectToVehicle you could use SetPlayerAttachedObject and make the ufo bigger.