Merfolk

Merfolk are beings that look uncannily similar to elves above the waist but have large powerful fish-like tails. The are fast, agile, and have a carefree attitude, though they can be extremely serious in matters of protecting the ocean and its ecosystems. Should anything threaten the sanctity of the water's purity, they are sure to respond.

ability score increase: DEX +2, CHA +1

age: Merfolk can live up to 300 years

alignment: Usually good or neutral, though there are some who choose evil

Size: Medium

speed: 20 ft walking; 50 ft swimming.

Languages: Common, Aquan

race features:

Amphibious. You can breath both air and water.
Slippery. You have advantage on Dexterity (Acrobatics) checks against being grappled and saving throws to avoid being restrained.
Darkvision. 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. While underwater you have darkvision, you can see in dim light within 120 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of grey.
Adaptable. At 5th level, you can transform your mermaid tail into two legs. While this is active, you have a walking speed of 20 feet but lose all of your swimming speed. You may undo this at any time.