Dawn's Piplup is Dawn's starter Pokemon. He debuted in Following a Maiden's Voyage.
Dawn received Piplup from Professor Rowan after befriending him. He is a target to Team Rocket who try to capture him for their boss. But he is always saved by his trainer.
Piplup tries his best to be loyal to his trainer, he is short-tempered and gets upset very easily for example in Piplup Up and Away when Dawn didn't pay attention to him, he ran away upset thinking Dawn didn't care for him, but she followed him and discovered why he had run away and tried to comfort him.