Leviathan Touched

One reason or another maybe from one of the many gods you worship or from your rigorous training you seem to have taken on the aspects of a Kuo-Toa Leviathan, gaining a slippery body,  better swimming, and the ability to grow larger than normal.

• Increase your Strength or Wisdom score by 1, to a maximum of 20
• Increase your swimming speed by 10 feet.
• You can cast enlarge on yourself when you so the spell lasts 1 minute and doesn't require concentration. Once you cast the spell with this trait you can't do so again until you finish a long rest or unless expend 2 hit dice as an action to regain the feature. Wisdom is your spellcasting ability for this spell.
• You have advantage on any ability checks and saving throws made to escape a grapple.