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