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