drain a creatures water

You send suck the water out of a living creature. The target must make a Constitution saving throw. It takes 7d8 + 30 necrotic damage on a failed to save, or half as much damage on a successful one. And they become dehydrated and become exhaustion. 

A humanoid killed by this spell rises at the start of your next turn as a mummy that is permanently under your command, following your verbal orders to the best of its ability. for one day before it dies.