A Pokemon Ranger is a Trainer Class introduced in Generation III. They are forest rangers seeking to help the environment and help people who are lost. They usually use Pokémon releated to nature. In Black and White, they will give you a Berry once you have defeated them.
In PMBW03, Monta challenges a Pokémon Ranger to a battle. Monta sends out an Emonga and his Tsutarja. The ranger sends out his Zebrstrika and Swanna. The ranger surprises Monta on the fact that none of his Emonga's electric attacks can hit Swanna due to the Zebstrika's Lightning Rod ability, an ability that draws electric attacks and deal no damage to the Pokémon with the ability. The ranger tells Swanna to attack Tsutarja. Monta then decides to switch Tsutarja to Doryuuzu and uses Sandstorm then Dig on Zebraika. The ranger isn't worried for he knows that Dig can't take out Zebraika completely but was astonished when Zebraika was defeated. Monta tells him that Doryuuzu's ability Sand Power increases his power when there is a sandstorm. Monta's Emonga uses an electric attack on Swanna and the battle is over.