accustomed to life in deep abbysal seas, you have darkvision out to 120 feet 

you can cast the shape water spell at will without any components, you can also cast the create or destroy water, fog cloud, and thunderwave spells 3 times a day each requiring no components, when you reach 3rd level you can cast the suggestion spell once a day requiring no components,  when you reach 5th level you can cast suggestion 3 times a day and the tidal wave  and wall of water  spells once a day each requiring no components, when you reach 7th level you can cast the control water spell once a day requiring no components and the tidal wave  and wall of water spells three times a day each, when you reach 11th level you can cast the bigbys hand and cone of cold spells once a day each requiring no components

 Your constitution increases by 5, your strength increases by 2 and your dexterity decreases by 3

Oceanbanes reach maturity at 300, and can live over 10000 years

you can breathe air, and water, you also have resistance to fire, acid, and lightning damage

Baby oceanbanes are larger than humans but are very small compared to there parents they  are usually between 9 and 23 feet tall and weigh between 370 and 1000 pounds, your size is large.

Your base walking speed is 10 feet and you have a swimming speed of 90 feet.

your unarmed strikes deal 1d6 + strength bludgeoning damage and 1d4 acid damage(or 1d6 at 5th level, 1d8 at 10th level, 1d10 at 15th level, and 1d12 at 20th level ), you cant wield weapons, and armor must be made especially for you costing an additional 50 gold pieces.

You can speak, read, and write Common, Abbysal, And Aquan. you know the languages of demons and water creatures being a mix of them