At 1st level, choose one of the following options:

Manta Glide. You have ray-like fins that you can use as wings to slow your fall or allow you to glide. When you fall and aren't incapacitated, you can subtract up to 100 feet from the fall when calculating falling damage, and you can move up to 2 feet horizontally for every 1 foot you descend.

Nimble Climber. You have a climbing speed equal to your walking speed.

Underwater Adaptation. You can breathe air and water, and you have a swimming speed equal to your walking speed.

At 5th level, your body evolves further, developing new characteristics. Choose one of the options you didn't take at 1st level, or one of the following options:

Grappling Appendages. You have two special appendages growing alongside your arms. Choose whether they're both claws or tentacles. As an action, you can use one of them to try to grapple a creature. Each one is also a natural weapon, which you can use to make an unarmed strike. If you hit with it, the target takes bludgeoning damage equal to l d6 +your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike. Immediately after hitting, you can try to grapple the target as a bonus action. These appendages can't precisely manipulate anything and can't wield weapons, magic items. or other specialized equipment.

Carapace. Your skin in places is covered by a thick shell. You gain a +1 bonus to AC when you're not wearing heavy armour.

Your Constitution score increases by 2, and one other ability score of your choice increases by 1. But tasha's allows you to customize your origin and choose any ability score.

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 can't discern colour in darkness, only shades of grey.

You can speak, read, and write Common and your choice of Elvish or Vedalken.