Pokémon evolution

Pokémon evolution is the process that some Pokémon take to take on a new form. The process is triggered in a wide verity of ways, including leveling, friendliness, and exposure to various types of stones.

Leveling
The most common process of evolution is simply gaining a particular level. For instance, the Pokémon Caterpie evolves into Metapod upon reaching level 7 (or any level following that). Many times Pokémon also have a second evolution that is also reached by leveling, as in Metapod reaching level 10 (or any level following that) and evolving into Butterfree.


 * List to be added later if needed

Stone Evolution
Introduced in the original set of Pokémon games, stone evolution was once the second most common type of evolution. The idea is that when you are ready to evolve a Pokémon that evolves through a stone, you would find or buy the correct stone and "use" it on that Pokémon, inducing evolution. An early example of this is Pikachu evolving into Raichu when a Thunderstone is used on it.

List of Pokémon that evolve through stone:


 * Pikachu -> Raichu w/ Thunderstone
 * Nidorina -> Nidoqueen w/ Moon Stone
 * Nidorino -> Nidoking w/ Moon Stone
 * Clefairy -> Clefable w/ Moon Stone
 * Vulpix -> Ninetales w/ Fire Stone
 * Jigglypuff -> Wigglytuff w/ Moon Stone
 * Gloom -> Vileplume w/ Leaf Stone
 * Gloom -> Bellossom w/ Sun Stone
 * Growlithe -> Arcanine w/ Fire Stone
 * Poliwhirl -> Poliwrath w/ Water Stone
 * Weepinbell -> Victreebel w/ Leaf Stone
 * Shellder -> Cloyster w/ Water Stone
 * Exeggcute -> Exeggutor w/ Leaf Stone
 * Staryu -> Starmie w/ Water Stone
 * Eevee -> Vaporeon w/ Water Stone
 * Eevee -> Jolteon w/ Thunderstone
 * Eevee -> Flareon w/ Fire Stone
 * Sunkern -> Sunflora w/ Sun Stone
 * Lombre -> Ludicolo w/ Water Stone
 * Nuzleaf -> Shiftry w/ Leaf Stone
 * Skitty -> Delcatty w/ Moon Stone
 * Roselia -> Roserade w/ Shiny Stone
 * Misdreavus -> Mismagius w/ Dusk Stone
 * Murkrow -> Honchkrow w/ Dusk Stone
 * Togetic -> Togekiss w/ Shiny Stone
 * Kirlia -> Gallade w/ Dawn Stone
 * Snorunt -> Froslass w/ Dawn Stone

Trade Evolution
Also a first generation evolution process, when a player trades a particular Pokémon to another game, that Pokémon will then evolve. A new step was introduced in the second generation that involved having the Pokémon hold a particular item to induce the evolution.

List of Pokémon that evolve through trade (no hold items):
 * Kadabra -> Alakazam
 * Machoke -> Machamp
 * Graveler -> Golem
 * Gastly -> Gengar

List of Pokémon that evolve through trade with hold items:
 * Poliwhirl -> Politoed w/ King's Rock
 * Slowpoke -> Slowking w/ King's Rock
 * Onix -> Steelix w/ Metal Coat
 * Scyther -> Scizor w/ Metal Coat
 * Seadra -> Kingdra w/ Dragon Scale
 * Porygon -> Porygon-2 w/ Up-Grade
 * Clamperl -> Huntail w/ DeepSeaTooth
 * Clamperl -> Gorebyss w/ DeepSeaScale
 * Rhydon -> Rhyperior w/ Protector
 * Electabuzz -> Electivire w/ Electirizer
 * Magmar -> Magmortar w/ Magmarizer
 * Porygon-2 -> Porygon-Z w/ Dubious Disc
 * Dusclops -> Dusknoir w/ Reaper Cloth