The following is a list of subraces for goliaths.
Cloud Giant[]
Ability Score Increase. Your Constitution score increases by 1.
Keen Smell. You have advantage on Wisdom (Perception) checks that rely on smell.
Cloudy Magic. You have the ability to innately cast the spells detect magic and fog cloud. At 5th Level, you gain the ability to innately cast feather fall, but must take a long rest to regain this ability. At 10th Level, you gain the ability to innately cast gaseous form, but must take a long rest to regain this ability.
Fire Giant[]
Ability Score Increase. Your Constitution score increases by 1.
Fire Forged. Your body produces a strong amount of natural heat. You gain resistance to fire damage. When you reach 10th level, this trait becomes immunity to fire damage and you can even walk through lava without being harmed.
Martial Expert. You gain proficiency with all martial weapons.
Frost Giant[]
Ability Score Increase. Your Strength score increases by 1.
Heart of Frost. Because you are a being of frost, you gain resistance to cold damage. When you reach 10th level, this trait becomes immunity to cold damage and you cannot be slowed by cold.
Make War, Not Goods. Frost goliaths care little for gold and money. Instead, what they take, they seek to forge into weapons of War. You gain proficiency with smith's tools.
Hill Giant[]
Ability Score Increase. Your Strength score increases by 1.
Bigger Means Better. If you are wielding a weapon that deals 2d6 damage that you have proficiency with, you deal an additional 2 damage of the weapon's type.
Inbred Stupidity. Because your people were born of inbreds, you lack a lot of intelligence. When you make an Intelligence check for either Arcana, History, or Nature, you roll with disadvantage.
Stone Giant[]
Ability Score Increase. Your Dexterity score increases by 1.
Stone Camouflage. You have advantage on Dexterity (Stealth) checks made to hide in rocky terrain.
Rock Catching. If a rock or similar object is thrown at you, you can make a DC 14 Dexterity saving throw to catch the rock and take no damage.
Storm Giant[]
Ability Score Increase. Your Constitution score increases by 1.
Amphibious. You can breathe air and water.
Stormy Magic. You have the ability to innately cast the spells detect magic and feather fall. At 3rd Level, you gain the ability to innately cast levitate, but must take a long rest to regain this ability. At 8th and 14th Level, you gain an extra use of this ability before you must take a long rest. At 10th Level, you can innately cast Lightning Bolt, but must take a long rest to regain this ability. You use your Intelligence modifier for this spell.
Keepers of History. You are knowledgable in all things involving history and thus have proficiency in History.