The complete Pokemon Diamond and Pearl pokedex, part 1

Pokémon Name: Empoleon
Type: Water / Steel
Classification: Emperor
Pokédex Number: 009 Sinnoh / 395 National
Ability: Torrent – Increases the power of Water-type attacks when HP is low
Dream World ability: Defiant – User's Attack stat raises two stages for every stat lowered by an opponent (including Attack)
Useful Attacks: Drill Peck

Location Found:

Evolved from Prinplup
HG/SS: Trade from D/P/P
B/W: Poke Transfer

The mystery of Prinplup's Metal Claw attack is solved at last – Empoleon, Piplup's final evolution, has a secondary Steel type. The crown-like protrusion growing from Prinplup's beak has spread to cover its entire body in an impenetrable and regal body armor. While Empoleon is slow-moving and has a fairly limited repertoire of powerful moves, its impressive HP, defense and Steel type allow it to take a lot of punishment.