Ariana Grande (Then)
Playing the delightfully bubbly Catarina “Cat” Valentine, Ariana Grande expressed her character wasn’t the most liked among fans due to her overly sensitive and “ditzy” personality. Toward the end of the fourth season, she manages to win the affections of Robbie. Before her acting debut on Victorious, Grande made two uncredited appearances on “iCarly” and provided the voice for Princess Diaspro in “Winx Club: Enchantix.”