I'm trying to ID an animated feature about two dragons I saw as a child. There is an old, wise dragon and a young dragon who is something of an apprentice. Part of the plot has them preparing to fight an evil ogre. The older dragon teaches the younger how to fight the ogre, but when the younger finally encounters the ogre (atop a castle I believe) the ogre gets the upper hand. Right before the ogre delivers a death blow to the younger, the older dragon saves him by slamming into the ogre and sending them both falling to their deaths. Does anyone know the title of this film?