A 巨型卷壳怪 is an 敌怪 found in the 洞穴s layer. They attack by curling into their shells and hurling themselves at players, though they will stall in midair and drop to the ground if they are damaged during their flight. Giant Shellies attack very quickly and deal high damage for the stage in the game where they are found.
Giant Shellies are unique in that their ability to spawn is connected to two other enemies: the 龙虾 and the 蝾螈. Of these three enemies, a world will choose two types that it can spawn, leaving the third inaccessible. Giant Shellies will never spawn in a world that features both Crawdads and Salamanders together.