Duraludon is a tall bipedal dinosaur-like Pokémon with large feet, a chunky tail, and a head integrated to its neck. Its body is mainly light gray and dark blue, with zigzag patterns running down its body, gray bands around its arms, and two black slits on its lower chest. Its hands have four triangular indents. Duraludon's head has a small red section and multiple slits on it. It also has yellow eyes with green pupils, and it appears to be permanently scowling. It moves its upper jaw when opening its mouth.
Duraludon's body is made of strong, but surprisingly light metal. Weighing only 88 lbs. (40 kg), it can move very fast. However, its body can easily rust, so it lives in caves and mountainous areas and avoids rain. It uses its arms, which have slightly different shapes from each other, to grind down rock surfaces for food. Duraludon has a rivalry with Tyranitar, which it shares its habitat with, and they often battle each other in the mountains of Galar.
Gigantamax Duraludon is much larger and resembles a skyscraper. It has a massive glass plate on its abdomen, and its chest has glass panels that resemble windows. It also gains a horn-like protrusion on its head, and metal strips on its feet resembling toes. Three red clouds surround its neck. In its Gigantamax state, parts of its body glow due to an abundance of energy. The cells in its body are exceptionally durable, even among Steel-type Pokémon, and it is resistant to earthquakes thanks to its body structure.
Gigantamax Duraludon is the only known Pokémon capable of using the exclusive G-Max Move G-Max Depletion.
Duraludon and especially its Gigantamax form seems to be based on The Shard, the tallest building in the United Kingdom. Based on its name, the metal that covers its body is presumably duralumin, an aluminum-copper alloy that is strong and light, but not very resistant to corrosion. Its rivalry with Tyranitar may be a reference to the kaiju genre of films. Its overall body shape resembles a theropod dinosaur.
Duraludon may be a combination of duralumin, durable, dragon, don (Spanish for lord), and -don (common suffix in dinosaur names derived from the Ancient Greek word for tooth).