It is not known to evolve into or from any other Pokémon.
Dialga is the version mascot of Pokémon Diamond, appearing on the boxart.
Dialga is a dark blue sauropod-like Pokémon with some gray metallic portions, such as its chestplate, which has a diamond in the center. It also has various light blue stripes. It has a fin-like structure on its back and a crest on its head, resembling a dinosaur. Dialga also has two horns on top of its head, two fang-like horns around its mouth, three spines on the back of its neck, long claws, and a short tail. The wing-like structure on its back can be used to focus the flow of time, as seen in Explorers of Time, Darkness, and Sky.
Dialga can warp time by either speeding it up, slowing it down, or stopping it altogether. As Dialga primarily resides in a different dimension, its behavior is nearly impossible to study. It has been shown to be very protective of its home. It also tends to have violent conflicts with its counterpart, Palkia. Dialga is the only known Pokémon that can learn Roar of Time.
In the anime
Dialga appeared in the first three Diamond & Pearl series Pokémon movies. It was first shown in The Rise of Darkrai, where it fought with Palkia and Darkrai in a battle that nearly destroyed Alamos Town. The same Dialga appeared in Giratina and the Sky Warrior. On its return trip back to its own dimension, Dialga ended up in the Reverse World and got attacked by Giratina. The Renegade Pokémon had been angered by Dialga and Palkia's fight in the previous movie. Dialga's final movie appearance was in Arceus and the Jewel of Life. It was shown for the first time with both the other members of its trio. After being called by Sheena to stop a spatial distortion, it briefly fought with Giratina once more. Later, it returned to help Palkia and Giratina fight Arceus, and sent Sheena, Ash and his friends back in time to fix Arceus's betrayal.
Dialga made its debut in A Secret Sphere of Influence! in a fantasy.
An evil Dialga made two brief appearances in Pokémon Mystery Dungeon: Explorers of Sky - Beyond Time & Darkness as the protector of the Time Gear.
- Dialga co-starred with Xiro in the role of Samson in the LionKingHeart Fantasy Films crossover, "Sleeping Lioness."
- Diaga made a cameo appearance in Benny, Leo and Johnny's Adventures of Sleeping Beauty.
- Dialga will meet Pooh and his friends in Pooh's Adventures of Pokemon: The Rise of Darkrai.