This article is incomplete. Please feel free to edit this article to add missing information and complete it. Reason: number of times required to do something in order to get some of the medals
Medals (Japanese: メダルMedal) are a type of achievement in Pokémon Black 2 and White 2. They are stored in the Medal Box. There are 255 Medals in all, along with the Hint Medal. They are divided into five categories: 7 Special Medals, 98 Adventure Medals, 56 Battle Medals, 75 Entertainment Medals, and 19 Challenge Medals.
Win the Pokémon League with only Fire-type Pokémon.
Water-type Champ
みずチャンプ
Win the Pokémon League with only Water-type Pokémon.
Electric-type Champ
でんきチャンプ
Win the Pokémon League with only Electric-type Pokémon.
Grass-type Champ
くさチャンプ
Win the Pokémon League with only Grass-type Pokémon.
Ice-type Champ
こおりチャンプ
Win the Pokémon League with only Ice-type Pokémon.
Fighting-type Champ
かくとうチャンプ
Win the Pokémon League with only Fighting-type Pokémon.
Poison-type Champ
どくチャンプ
Win the Pokémon League with only Poison-type Pokémon.
Ground-type Champ
じめんチャンプ
Win the Pokémon League with only Ground-type Pokémon.
Flying-type Champ
ひこうチャンプ
Win the Pokémon League with only Flying-type Pokémon.
Psychic-type Champ
エスパーチャンプ
Win the Pokémon League with only Psychic-type Pokémon.
Bug-type Champ
むしチャンプ
Win the Pokémon League with only Bug-type Pokémon.
Rock-type Champ
いわチャンプ
Win the Pokémon League with only Rock-type Pokémon.
Ghost-type Champ
ゴーストチャンプ
Win the Pokémon League with only Ghost-type Pokémon.
Dragon-type Champ
ドラゴンチャンプ
Win the Pokémon League with only Dragon-type Pokémon.
Dark-type Champ
あくチャンプ
Win the Pokémon League with only Dark-type Pokémon.
Steel-type Champ
はがねチャンプ
Win the Pokémon League with only Steel-type Pokémon.
One and Only
ワンアンドオンリー
Win the Pokémon League with only one Pokémon in the party
Supreme Challenger
チャレンジジーニアス
Obtain all 18 other Challenge Medals
Trivia
Defeating the Elite 4 using a single dual-type Pokemon will unlock two Challenge Type Medals. For example, using Dragonite will unlock both Flying-Type Champ and Dragon-Type Champ.
Passing the same individual player 1000 times could unlock the the "Heavy Traffic" medal if the player saves and restarts after each tag. The same applies to the lower numbers.