Fed It Lives, Given a Drink It Dies — What Is It?

The answer is fire. Fire grows when you feed it fuel, but pouring water on it puts it out.

Fire 'lives' and spreads when fed wood, oil, or other fuel, but it 'dies' the moment it is given water — so the thing described is fire.

Think of something that lives on fuel and dies in water. It needs feeding to keep going but cannot survive a drink.