Naclstack is a quadrupedal Pokémon whose body is made of rock salt. Its cubic head is white with a few cracks and two eyes in the shape of right angles. Each of the eyes are orange in color with yellow squares at their centers, and they can glow an orange-red. The head is connected to Naclstack's body; the upper half of the body consists of a brown cuboid stone at the front and a rugged, dark brown rock dotted with salt at the back, while the lower body is a single white cuboid. Naclstack's body doesn't connect to its legs and floats in place relative to them. The legs themselves are cube-shaped, with light brown on top and white at the bottom. Each of the cubes have a small brown stone on one of their corners, which seem to act as claws for the Pokémon.
Naclstack attacks by pressing the rock salt inside its body into hardened pellets, which it then shoots out with enough force to puncture an iron sheet. Naclstack also uses its salt to dry out and cure its prey. The forgetful Naclstack often loses track of its salt-cured prey. This absent-minded Pokémon frequently forgets the commands given by its Trainer. Naclstack leaves behind bits of salt on its footprints as it walks; these salt grains are gathered by people and used as seasoning for sandwiches.
Due to a duplicated entry in the spawner data in Pokémon Scarlet and Violet, Naclstack effectively has twice its programmed spawn weight; making the Pokémon more common than intended.
Naclstack is the only Pokémon whose Japanese name contains the uncommon yotsugana ヅ (du or zu).
Similarly, Charjabug's Japanese name (デンヂムシ Dendimushi) is the only one that contains the uncommon yotsugana ヂ (di or ji).
Naclstack may be a combination of NaCl (chemical formula for sodium chloride; table salt) and stack, possibly in reference to dry stack (method of stone structure building that doesn't use mortar).
Jiodumu may be a combination of 塩 shio (salt), geo- (prefix for earth) or geode, and 積む tsumu (to stack).
This Pokémon article is part of Project Pokédex, a Bulbapedia project that aims to write comprehensive articles on each Pokémon species, as well as Pokémon groups and forms.