Dawn's Piplup (ヒカリのポッチャマ Hikari's Pochama) is a cute but stubborn Water-typePokémon. It was chosen by Dawn after they saved each other from the group of wild Ariados. Piplup doesn't really seem to like the idea of evolving, so it holds an Everstone. Though Piplup is a male, he wears cheerleading outfits while cheering for Dawn in contests.
Dawn's Piplup can be stubborn at times and it's also very proud like Piplup are. Overall, though, it is loyal to Dawn, and has helped her and her friends many times both in and out of battle (but always got lost when leading). Piplup has been shown that he deeply cares about Dawn, such as in the episode 'Stopped In The Name Of Love' where Piplup's time for evolution has finally come. Piplup however refused to evolve feared to start disobeying Dawn just like her Mamoswine after evolving from Piloswine. In order to stop his evolution, Piplup transferred the energy of evolution powering up his attack Bide. Dawn respected Piplup's choice as she got an Everstone from Nurse Joy and decided to keep it by her side. Piplup has also been shown to have developed some kind of rivalry with baby Cyndaquil regarding Dawn's attention.
Piplup has recently become a target of Gible's Draco Meteor attacks as every Gible's Draco Meteor manages to hit Piplup no matter where he is. In the episode 'Piplup Gets Separated', Piplup is once again hit by the move but is even more saddened when he notices that Ash and Dawn are paying more attention to Gible than to him. Jealous, Piplup runs away only to bump into disguised Team Rocket who pretend to be the aids of Prof. Rowan. Suddenly, a wild Rhyperior starts rampaging splitting everyone up. In the same episode in order to save Dawn, Piplup learns a powerful move, Hydro Pump and so manages to attack Rhyperior.