Pierre wished that all French people would be rude to Americans, and lost his godparents for it. He was wished out of his painting by Timmy because he believed he was in the Hall of Fame (he was really in the Hall of Infamy). He was going to use Cosmo and Wanda's magic to get revenge, but Timmy put him back into his painting before he did any more harm.
A running gag with Pierre is that he translates some of his quotes to English after saying them, but all of his quotes were just him laughing with his accent since he says the translations without his accent.
His Laugh of "Ha Ha!" is based on the same laugh often uttered by Nelson Muntz from the Simpsons.