Dialga is a dark-blue, sauropod-like Pokémon with metallic gray sections and light blue stripes. It features a chest plate adorned with a deep blue diamond-shaped crystal in the center. The Pokémon has a fin-like structure on its back, three spines at the rear of its neck, and a crest on its head that resembles a dinosaur. The crest looks somewhat like a sundial's rod. Additionally, it has two protrusions on the sides of its head that resemble horns or fangs. Its feet have three claws each, matching the metallic look of its chest plate. Faint cracks are visible across its body. The fin-like structure on its back can focus the flow of time, as seen in Pokémon Mystery Dungeon: Explorers of Time and Darkness and Sky. Dialga typically travels by levitation rather than walking.
Dialga controls time, capable of speeding it up, slowing it down, reversing it, or stopping it altogether. It can traverse different eras, past, present, and future, and even create or destroy time itself. In the anime, Dialga's temporal abilities can devolve creatures against their will, including Pokémon, humans, and plants, and reverse these effects. Time began when Dialga was born and continues as long as its heart beats. Dialga can create new universes alone or with Palkia. As it resides in another dimension, studying its behavior is nearly impossible. In its home dimension, time moves in various directions and speeds. Dialga fiercely protects this realm and often clashes violently with Palkia.
In Sinnoh myths, Dialga was revered as a deity, worshipped by the Diamond Clan who called it "almighty Sinnoh." Dialga communicates through telepathy, demonstrated when speaking to the Diamond Clan leader, Adaman. Both Dialga and Palkia manage space-time distortions caused by Giratina, which generate alpha Pokémon and cause Noble Pokémon to go berserk.
Forms
Dialga shifts between its standard form and Origin Forme. Considered its true form, Origin Forme drastically differs from its usual sauropod appearance, blending elements of a dragon and centaur while resembling its creator, Arceus. Its hind legs become unguligrade with pointed tips, and its front legs grow larger with rhomboid claws. Dialga’s knees develop rectangular protrusions. Its chest plate disappears but leaves a polygonal shape behind. A large structure juts out from its neck, accompanied by wing-like protrusions containing deep blue crystals. The neck spines lengthen and sharpen. Two arrow-shaped horns extend from Dialga’s head, alongside longer fang-like horns connected to a lower jaw mask. Around its abdomen is a cross resembling Arceus’s cross-wheel. The posterior fin has a star-shaped layer atop it, and the tail becomes shorter and crystal-shaped. Overall, Dialga grows larger, darker blue, with light blue accents on specific parts.
In Origin Forme, Dialga reaches full power, likely remaining in this form within its home dimension. Transformation into Origin Forme is triggered by radiant light or using the Adamant Crystal. This form enables Dialga to unleash meteors and shockwaves, enhancing its Roar of Time technique. Crystals and light blue accents glow brightly when Dialga uses its powers, evident in its boss battle in Pokémon Legends: Arceus.
