Perfect Peter is a main character in the Horrid Henry series. He is the younger brother of the series' protagonist, Horrid Henry. Peter is named according to his overachieving, polite, and perfectionist personality and mannerisms, especially in opposition to those demonstrated by his older brother Henry.
Peter appears as an Assist Trophy in All Star Smashers. When summoned, he will play his violin, replacing the stage's music. The closest character will then have a tantrum attack. If Peter gets attacked, then his mum will appear in his place, scolding the opponent who attacked Peter for his/her disgraceful behaviour. She will then star KO that opponent. After Peter leaves, the stage's music returns to normal.
Whenever Henry torments Peter, he will often call out to his mum to deal with Henry. The part of him playing the violin is based on the fact that he is shown to be skilled at music, to the point where his parents often ask him to play the violin to impress their visitors.