Location: New Bark Town

Method:
Naturally, the first Pokémon you obtain is the starter Pokémon. Like in all games, once you have chosen your starter, your rival will pick the Pokémon that is super effective against yours

Chikorita Level 5

OT: Yours ID: Yours Hold Item: None

Tackle Growl

Cyndaquil Level 5

OT: Yours ID: Yours Hold Item: None

Tackle Leer

Totodile Level 5

OT: Yours ID: Yours Hold Item: None

Scratch Leer

Location: Goldenrod City

Method:
The first gift Pokemon you are likely to encounter is in the form of a carrier pidgeon Spearow. The Pokemon's trainer is encountered on Route 35 and the destination is Route 31. Spearow comes holding mail which you can simply transfer to another Pokemon if you wish to keep the tiny bird Pokemon. Upon delivery of the mail, you will receive TM50 Nightmare.

KENYA Level 10

OT: RANDY ID: Yours Hold Item: Flower Mail

Peck Growl Leer

Location: Goldenrod City

Method:
After meeting Bill in Ecruteak City, head back to Goldenrod City and find his house. Along with getting a phone number for the PC from his sister, you can pick up an Eevee of his for free. The Eevee comes at Level 20 and is Normal-type so it'll be useful against the Ecruteak Gym when it learns Bite or Mud-Slap. Although it has five evolutions, Espeon or Umbreon are the ones you'll be most likely to see because of the rarity of evolutionary stones in these game. Both are also excellent for the Ecruteak Gym.

Eevee Level 20

OT: Yours ID: Yours Hold Item: None

Tackle Sand-attack Growl

Location: Dragon's Den

Method:
After defeating Clair and earning the badge, one of the monks will give you a test. If you answer correctly, stating that you think of Pokémon as friends, rather than tools, you will receive a special Dratini with the special move of Extremespeed. If you answer that the Pokémon are just tools, you'll receive a Dratini without Extremespeed

Dratini Level 15

OT: Yours ID: Yours Hold Item: None

Wrap Leer Thunder Wave Twister

Dratini Level 15

OT: Yours ID: Yours Hold Item: None

Wrap Thunder Wave Twister Extremespeed

Location: Violet City

Method:
The egg that you had at the beginning of the game will be given back to you after beating Falkner, should you go to the Violet City Pokemon Center. The egg should hatch into Togepi by the time you reach Goldenrod City. Togepi doesn't know any attacking moves when it hatches so you'll have to baby it for a while before using it in battle. However, upon evolution it gains a formidable Special Defense and decent Special Attack stat in Togetic.

Togepi Level 5	OT: Yours ID: Yours Hold Item: None	Growl
This Pokémon comes within an Egg and requires hatching

Location: Cianwood City

Method:
After having all of his Pokemon stolen by your rival, a guy in Cianwood City will entrust to you his Level 15 Shuckle for safekeeping. The mold Pokemon can only be acquired through Rock Smash in Cianwood City and Vermilion City otherwise so it may be worth your while to pick this one up. Although its defenses are stellar, it has pitiful Attack and Special Attack and learns very few useful moves. An interesting quirk is that giving Shuckle a Berry will create Berry Juice some time after. Mania will want his Shuckle back after you keep it for a while, though it is up to you whether you want to give it back or not.

SHUCKIE Level 15

OT: MANIA ID: 00518 Hold Item: Berry

Constrict Withdraw Wrap Encore

Location: Mt. Mortar

Method:
Deep inside Mt. Mortar lies the Karate King. He will challenge you to a battle with a Level 34 Hitmonchan and Level 34 Hitmonlee. This battle is very similar to the one in Red and Blue against him so whatever tactics you used against him then will work here. Upon defeat he will give you a Level 10 Tyrogue, which can evolve into Hitmonchan, Hitmonlee, or Hitmontop depending on its stats. You must have less than six Pokemon in your party to get Tyrogue will will need to climb the Waterfall in the middle Mt. Mortar entrance to meet the Karate King.

Tyrogue Level 10

OT: Yours ID: Yours Hold Item: None

Tackle

Location: Route 34

Method:
In addition to the Togepi egg from Gold and Silver, players can obtain a second egg in the Crystal version. This egg can hatch into any of the baby Pokemon, allowing players to potentially receive their favourite Pokemon far earlier in the game than normal, with the special move Dizzy Punch as an added bonus. This page details how to get it in both the Japanese and International versions.

Japanese Version
In the Japanese version, players get an Egg Ticket from the Day Care Man which must be redeemed at the Pokemon Communication Center in Goldenrod City. Any of the baby Pokemon have a 50% rate of being shiny.

International Version
With the removal of the PCC in the international releases the method for getting the second egg has been simplified. The Day Care Man will now simply give you the egg - no need for an Egg Ticket. The rate at which the hatched Pokemon can be shiny has been reduced to 14% for these versions, but the Pokemon remain the same.

Pichu Level 5

OT: Yours ID: Yours Hold Item: None

Thundershock Charm Dizzy Punch

Cleffa Level 5

OT: Yours ID: Yours Hold Item: None

Pound Charm Encore Dizzy Punch

Igglybuff Level 5

OT: Yours ID: Yours Hold Item: None

Sing Charm Defense Curl Dizzy Punch

Tyrogue Level 5

OT: Yours ID: Yours Hold Item: None

Tackle Dizzy Punch

Smoochum Level 5

OT: Yours ID: Yours Hold Item: None

Pound Lick Dizzy Punch

Elekid Level 5

OT: Yours ID: Yours Hold Item: None

Quick Attack Leer Dizzy Punch

Magby Level 5

OT: Yours ID: Yours Hold Item: None

Ember Dizzy Punch