Mr. Tang first appears in this episode. He is part of a running gag with all the parents, whom break down their child's bedroom door with a battering ram while saying "I'm respecting your privacy by knocking but coming in anyway". He then gleefully hands the phone to Trixie.
Mr. Tang is seated behind Timmy and next to his daughter in the school auditorium during the Parent Talent Night show. He has no speaking role.
Mr. Tang is alongside Trixie during a Student-Parent Movie Night being held at the school. He and his daughter are characters from Casablanca. He has no speaking role.
Mr. Tang is one of the many parents protesting the out of control behavior by their kids during the summer. He appears in several songs, but has no speaking roles outside of them.
When Timmy Turner arrives at the Tang Mansion to stop a killer plant he had given to Trixie earlier from eating her, Mr. Tang answers the door. Even though it is late at night, Timmy is dressed oddly and carrying sharp objects, and has a crazed look in his eyes, Mr. Tang thinks none of it and politely lets Timmy into his house to see Trixie.