You are a humanoid, however, you can easily be mistaken for an undead

You are Medium (about 4–6 feet tall)

Your speed is 30 ft

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. water

Because of their life on the water. water-bound have developed sealegs making it hard for them to get knocked over even in the most extreme cases of wild waves. 

Water-bound get advantage on saving throws against getting pused or moved as well as getting knocked prone. You will never get pushed, moved or knocked prone if the surface you're standing on is a liquid or humid by a liquid.

You gain access to the spell Create or Destroy Water at 5th level, and Shape water at 3rd level.

Because of your flexibility with the waves of the water you've learned how to use the water as an advantage to move quicker then usual.

Because your mirror image has a physical form and perfectly copies your movement you gain the abilty to walk on any liquid surface (water walk) but cant turn it off. In other words you can only walk on liquid surfaces, not swim

When determining ability scores, increase your dexterity score by 1, and increase your wisdom score by 2.

Your character knows at least three languages: Common plus two languages you roll or choose from the Standard Languages table. Knowledge of a language means your character can communicate in it, read it, and write it. Your class and other features might also give you languages.

The Standard Languages table lists languages that are widespread on D&D worlds. Every player character knows Common, which originated in the planar metropolis of Sigil, the hub of the multiverse. The other standard languages originated with the first members of the most prominent species in the worlds of D&D and have since spread widely.