HeartGold Exclusive Pokemon
Many sets of Pokemon evolutions are exclusive to "Pokemon HeartGold." From the first set of 150 Pokemon, Mankey, Primeape, Growlithe and Arcanine can be found only in the "HeartGold" version. Spinarak, Ariados, Gligar, Phanpy and Donphan represent exclusive monsters from the expanded 251 Pokedex. Sableye, Baltoy and Claydol are select creatures that first appeared when the Game Boy Advance Pokedex reached 386 unique creatures. Mantyke and Glisor, the evolved form of Gligar, originated from earlier Nintendo DS Pokemon games. All of the aforementioned monsters are not available in "Pokemon SoulSilver."
SoulSilver Exclusive Pokemon
The vast majority of the 493 monsters are available in both versions, "Pokemon SoulSilver" holds its own share of exclusive beasts. The special Kanto Pokemon are Meowth, Persian, Vulpix and Ninetales. The Johto Region has a larger representation of exclusive monsters can only be found in "SoulSilver," such as Ledyba, Ledian, Teddiursa, Ursaring and Skarmory. Mawile, Gulpin and Swalot round out the creatures exclusively found on "Pokemon SoulSilver" that made their debut in the Hoenn Region.
Legendary Pokemon
Legendary Pokemon are often much stronger, faster and tougher than most other Pokemon. These rare beasts are divided up between "Pokemon SoulSilver" and "Pokemon HeartGold." For example, the legendary Ground Pokemon Groudon is only found on "Pokemon SoulSilver." Its counterpart, the Sea Basin Pokemon Kyogre awaits Pokemon Trainers in "Pokemon HeartGold." If both Kyogre and Groudon are imported into the same version, the player will be able to challenge Rayquaza.
Legendary Bird Events
Depending on the version you play, the game's story will have a stronger focus on one of the two Johto legendary birds -- Lugia or Ho-Oh. In "Pokemon HeartGold," the game takes the player to the top of the Bell Tower after beating Team Rocket and the Kimono Girls. While in "Pokemon SoulSilver," players are given early access to Lugia in the Whirl Islands. The other powerfully strong bird Pokemon is located after the player beats the Elite Four and obtains a Wing item from Pewter City that unlocks the path to the bird. Whether it is Lugia or Ho-Oh, the first bird encountered will be at Level 45 and the other will be at stronger Level 70.