Pappy Popper was the customer in the Mopatop's Shop episode "Pop Star". He is looking for a new pop sound since he is tired of his. Puppyduck appears and Pappy Popper likes her whistle sound that he wants to swap his pop sound for it. He doesn't realize that Puppyduck's whistle sound belong to Moosey Mouse and Father Mouse was trying to fix Puppyduck's pop sound. Still, Mopatop swap his pop sound for Puppyduck's whistle sound and Pappy Popper happily leaves the store with his new pop sound.