>>37154608lol how, besides Pikachu (And Meowth) Piplup is the only pokemon with an actual memorable personality that goes through a character arc in the show.
He starts out weak but becomes one of Dawn's strongest pokemon throughout the show.
Starts out disliking Dawn at first but quickly develops a fondness for her, one that makes him get jealous of other pokemon easily (like Dawn's Cyndaquil). Piplup wants to be the one Dawn gives full attention and goes out of his way to impress Dawn. But Piplup is also quick to support Dawn in whatever she needs, be it support or a stern talking to.
Piplup has flaws. He's constantly overestimating his own worth and when things doesn't go his way he is quick to throw a tantrum. And his tantrums often times makes things worse for him.
Face it, Piplup was a unique character for DP and the best written pokemon probably since Pikachu itself. And since Piplup they've tried to create similar characters but failed again and again.