Empoleon was Dawn's first Pokémon, given to her by Professor Rowan when she started her Pokémon journey as a Piplup. Since then, it has been one of Dawn's most used and trusted Pokémon. As a Piplup, it was rather unruly, in fact, Empoleon and Dawn were far from bosom friends with they first started, and, despite helping Dawn capture her first Pokémon, a Starly, Piplup was far from cooperative until Dawn earned it's respect in one of her battles against her rival and longtime friend, Barry. From that point, Piplup proved it was a powerful contender, and helped Dawn in many battles, evolving into Prinplup and Empoleon during her journey to conquer the Elite Four and take down Team Galactic.
During it's youth as a Piplup, Dawn favored using it in Contests due to it's cute appearance, however, it was the evolution to Prinplup and Emploleon that forced Dawn to adapt to larger Pokémon in Contests, and overall shaped how the woman competed. As an Empoleon, it proves to be one of Dawn's most powerful battlers, taking advantage of it's Steel-type to provide a durable wall and still pack power, and is usually one of the last Pokémon she uses in official League battles, as a sign of respect to an opponent who has given her a good battle.
Empoleon is a large penguin-like Pokémon. In terms of color, it has a closer resemblance to a "real-world" penguin than its pre-evolved forms have because it is mostly navy blue as opposed to being a lighter blue. Its feet actually appear to have webbing on them. Its wings are tipped with blue metal and have three golden claws sticking out at the bottom. It has a short, blue, metal "fin" sticking out of its back and another "fin" that's on the front of its body that extends to where its chin would be then splits to form some sort of collar. This "collar" is probably because real penguins are said to be wearing "tuxedos," due to their black and white appearance. If one looks at Empoleon, it has a tie like fin in the middle of its belly, and the collar coming off it, this relates to the "tuxedo" of a penguin. There is a lace-like pattern of white coloration on its front, and it has two gold-colored spots on its upper-back. Its most prominent feature is the three-horned trident-like crest that extends from its beak. This crest represents an Empoleon's power and the leader of a colony of Empoleon, Prinplup, and Piplup will have the largest horns.
Empoleon can swim faster than a jet boat and, by using its razor sharp wings, can cut huge glaciers in a matter of seconds. Empoleon can jump and glide in the air like a penguin would on ice. It can also learn any attack that its pre-evolutions can learn, but Empoleon's attacks are stronger. As a fully-evolved Pokémon (and the final evolution of a Water-type starter Pokémon), Empoleon can learn Hyper Beam, Giga Impact, and Hydro Cannon.
Given their immense pride, Empoleon are surprisingly social creatures. They live in large colonies led by the oldest and most powerful male. The leader has the largest horns on its head.