HAHA you are forgetting, my friend, that "Create Water" is an Orison for Oracles that creates 2 gallons of pure water per level. It will take some preparation, but if you have an arcane caster who knows ray of frost - a Cantrip - just dig a hole, fill it with water and freeze it with the cold spells, then use it immediately! I mean, it takes a while, but I think a Frostfallen Zombie Dragon would be worth it, no? :P