A creature requires an amount of water per day based on its size, as shown in the Water Needs per Day table. A creature that drinks less than half the required water for a day gains 1 Exhaustion level at the day’s end. Exhaustion caused by dehydration can’t be removed until the creature drinks the full amount of water required for a day. See also “Exhaustion.” Water Needs per Day SizeWater Tiny1/4 gallon Small1 gallon Medium1 gallon SizeWater Large4 gallons Huge16 gallons Gargantuan64 gallons