What Pokémon can you only get in Diamond, Pearl or Platinum?

Version exclusives are the engine of Pokémon trading, and Sinnoh's are neatly paired. Diamond players meet Dialga at Spear Pillar while Pearl players meet Palkia, and the fossil each game revives easily is its own: Cranidos from the Skull Fossil in Diamond, Shieldon from the Armor Fossil in Pearl. The little exclusives mirror each other just as carefully, a skunk for Diamond against a cat for Pearl, a crow against a ghost.

Platinum keeps its own mascot encounter, Giratina, and keeps most of the pair's split, so a Platinum player still trades with both. But it loosens the screws elsewhere: both fossils can be dug up in its Underground, and Elekid and Magby, which Diamond and Pearl players could only flush out of the grass with a Game Boy Advance game in the second slot, simply live in Platinum's wild now.

One oddity worth knowing: wild Mr. Mime are a Diamond and Platinum find, wild Sudowoodo a Pearl and Platinum one, yet their babies, Mime Jr. and Bonsly, wander in both original games, so a patient Diamond player could still raise a Sudowoodo the slow way.