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