Avalugg is a massive Pokémon covered almost entirely in semi-transparent ice. Through the ice on its head, diamond-shaped, yellow eyes are visible. Its head is wedge-shaped with a white diamond-shaped ice chunk on each side in place of ears, a dark chink in the ice over each eye, a crack just before the tip of its snout, and a beard of short icicles. The top of Avalugg's body is flat with three horizontal cracks along the surface and there is a collection of icicles along its belly. Its legs are cylindrical with cracks just before its foot and in-between its toes; underneath each toe is a spiked claw. Pale purple colorations can be found on the insides of its cracks.
Avalugg's body is hard as steel, which allows it to crush anything in its way. It has been known to allow Bergmite to huddle on top of its back, which causes it to resemble an aircraft carrier. Avalugg carries the Bergmite on its back across oceans and to new habitats. During the day, the cracks in Avalugg's body deepen; they return to normal overnight. It lives in high altitudes, and co-exists with Cetitan.
Avalugg has an ancient regional form: Hisuian Avalugg.
Hisuian Avalugg is noticeably smaller than its Kalosian counterpart, weighing only half as much. Its entire body is made of brown stone, whilst its top, along with its head, are covered in a layer of solid ice. The head of Hisuian Avalugg is larger compared to Kalosian Avalugg, and has two large gray tusk-like plates on its lower jaw. These armored plates are stronger than steel, and allow Hisuian Avalugg to break through boulders easily and shovel through deep snow. Hisuian Avalugg live in steep mountains, and are known to be rather docile.
A special Hisuian Avalugg is worshiped by the Hisui people due to him being descended from one of the 10 ancient Pokémon who received a blessing from Arceus. He is one of the Noble Pokémon who resides in Alabaster Icelands watched by a Warden. This Hisuian Avalugg is much larger than others of his species, being similar to Dynamaxed Pokémon in size.
Hisuian Avalugg is the only known Pokémon capable of learning the move Mountain Gale.
Avalugg evolves from Bergmite.
In Hisui, Avalugg has a regional form that evolves from Bergmite.
- Avalugg and its Hisuian Form have the highest base Defense stat of all Ice-type Pokémon.
- Avalugg shares its category with Regice. They are both known as the Iceberg Pokémon.
- Avalugg is the only Pokémon with a base stat total of 514.
- As of Generation IX, Avalugg and its pre-evolved form are the only Pokémon that are in both the Monster and Mineral Egg Groups.
- Due to an oversight, Alpha Hisuian Avalugg are the same height as the average Hisuian Avalugg in their summary screen. Despite this, the alpha's model is still noticeably larger than a normal one in game.
Avalugg appears to be based on a tabular iceberg or a stalactite. It may be a representation of the submerged part of the iceberg, which is immense in comparison with the tip. Its body also resembles an aetosaur, or possibly a tortoise.
Avalugg's Ice type and being likened to an aircraft carrier may be a reference to Project Habakkuk, a plan conceived by the Allies in World War II to build an aircraft carrier from pykrete, a combination of ice and wood pulp. The cracks in its body deepen in daytime heat and heal throughout the night, which is likely a reference to the polar ice caps shrinking in the summer and expanding in the winter.
Hisuian Avalugg may be based on a mountain covered with glacier, or the glacier itself. It could also be inspired by permafrost, which consist largely of ice and rock. The ice plates covering its jaws have the same appearance and function as the blades of a snowplow, which are used to clear snow from a path. Its ability to break through rocks easily may be inspired by the process of plucking, which is how glaciers erode bedrock as they move. It barrelling down steep mountain paths could also be referencing avalanches.
Avalugg may be a combination of avalanche and lug (to carry or drag heavy objects, or a big/clumsy person).
Crebase may be a combination of crevasse and base.