Triton

Common Cultures: Collegiate, Cosmopolitan, Despotic, Imperial, Magocracy, Natural, Nomadic, Rural, Theocratic, Undersea, Warrior

Ancestry Traits

Size. Your size is Medium.
Speed. 30 ft., 30 ft. swim

Amphibious (1 point).
You can breathe air and water, and you have a swim speed equal to your walking speed.
Darkvision (1 point).
You can see in dim light within 60 feet of you as if it were bright light and in darkness as if it were dim light. You discern colors in that darkness only as shades of gray.
Emissary of the Sea (1 point).
You can communicate simple ideas to any Beast that has a swimming speed. It can understand your words, though you have no special ability to understand it in return. If you have the Friend of the Sea trait, you can also speak to Elementals and Monstrosities that have a swimming speed.
Guardian of the Depths (1 point).
Adapted to the frigid ocean depths, you have resistance to cold damage.

Paragon Options

Aquatic Predator

Your swim speed increases by 10 feet, and you gain Darkvision out to 120 feet while underwater. If you already have Darkvision, it instead extends by 90 feet while underwater. Additionally, while underwater, you have Advantage on attack rolls against creatures that don't have a swim speed, and creatures that don't have a swim speed have Disadvantage on saving throws against spells and abilities you use.

Triton Magic

You learn advanced magic of the triton kingdoms. You learn the create or destroy water spell and can cast it at will, without spending mana. You also learn your choice of two of the following spells: gust of wind, water walk, or warding wind. You can cast each of these spells once without spending mana and without material components. Once you do, you can't do so again until you finish a long rest. You can also cast these spells using mana if you can cast spells of the appropriate level.

Intelligence, Wisdom, or Charisma is your spellcasting ability for these spells when you cast them with this trait (choose when you select this culture).