+2 strength + 2 dexterity + 2 constitution - 1 intelligence - 2 charisma

The axattle can live as long as they shed their shells, they shed every 4 years and when they do their AC gets reduced to 12 + dexterity or constitution (whichever is higher) and they regrow their shells in 1d4 days.

Their torsos can go from 4 to 5 feet tall, the oldest get to 6 feet. Their bottom halves can reach 2 to 3 feet tall and the length can be 5 to 6 feet long, the oldest can even reach 8 feet.

Anything really.

If you move somewhere and there is an opponent to the left or right of the path you have plotted, you may attack them as a bonus action.

You have a natural weapon in the form of a horn. This horn does 1d8 piercing damage + strength, anyone hit by this must make a strength or dexterity saving throw or get gored. A gored opponent gets grappeld and takes 1d6 damage every turn from bleeding from the GIANT HOLE. To stop the bleeding you must patch up the GIANT HOLE with a successful dc 13 medicine check. If you move your full movement then attack with the horn you do 1d10 piercing damage instead, and if you dash you can stab with your horn for free (not even a bonus action) which will now do 1d12 piercing damage.

You have a AC of 14 + dexterity or constitution (whichever is highest)

Adapted to even the most extreme ocean depths, you have resistance to cold damage, and you ignore any of the drawbacks caused by a deep, underwater environment.

If you get hit by force damage and any of the damage die roll their maximum you get stunned.

You can move on difficult terrain without penalty and you may attack while climbing as normal (because your T E N  L E G S can hold you on a wall as a spider would climb)

You can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

You cannot be frighted or charmed by any servants of lolth, and you can walk through and on webs without penalty.

You can communicate simple ideas with beasts that can breathe water. They can understand the meaning of your words, though you have no special ability to understand them in return.

You can innately cast shape water, have immunity to bludgeoning and cold damage from water.

You may extend or retract your eye stalks as a bonus action. While your eye stalks are extended  you gain advantage with perception checks that require eyesight, by your AC drops by -2 and if your eyes get hit they get chopped off the stalks doing 2d4 damage (this damage can only bring you to 1 health) to you and giving you blindness until you regrow them in 1d4 days.

You know aquan, clack and one language of your choice. Clack is a language that consists of many clicks at different pitches and speeds only able to be made by attle mandibles.

You have advantage on stealth checks while in water.