Here is the full list of all 32 Another Crab's Treasure achievements.
Learn all adaptations.
Get your shell back.
Defeated Firth.
Try on every shell in the game.
Fully upgrade Kril's fork.
Shoot a crab with a gun.
Find a certain hero's helmet.
Defeated Praya Dubia.
Defeated Camtscha (For real.)
Defeated Camtscha.
Defeated Inkerton.
Defeated Petroch.
Defeated Roland.
Unlock all skills on the Path of The True Crab.
Defeated Voltai.
Unlock all skills on the Path of The Hermit.
Unlock all skills on the Path of The Predator.
Defeated the Ceviche Sisters.
Defeated the Scuttling Sludge Steamroller.
Defeated Pagurus.
Defeated Topoda.
Defeated Heikea.
Defeated the Consortium.
Defeated the Curdled Carbonara Connoisseur.
Purchase some insurance.
Defeated the Diseased Lichenthrope.
Start the treasure hunt.
Fall off a cliff.
Defeated Magista.
Defeated a miniboss.
Defeated Nephro.
Defeated the Royal Shellsplitter.