The last name of Felix and Polly is Baker.
Polly's last name is Porter, Polly Porter :) Her boyfriend / viancé, Waz (Warrick) last name is Jones, Waz Jones.
Italian
Kjellberg, his full name is Felix Arvid Ulf Kjellberg
Polly Maberly's birth name is Polly Lucinda Maberly.
Polly Lynn's birth name is Polly Ann Brooks.
Polly Holliday's birth name is Polly Dean Holliday.
Polly Draper's birth name is Polly Carey Draper.
Polly Jane Rocket Adams's birth name is Polly Adams.
Polyhymnia (Polly/Poly) O'Keefe
Felix Felicis, which is the name of a potion not a character. Felix Felicis is the liquid luck potion used in Harry Potter and the Half-Blood Prince.
Polly. Polly Kelby.
Felix Salzman's birth name is Felix Salzman.