The series focuses on the experiences of a courageous, adventurous one-year-old baby named Tommy Pickles and his group of playmates – several other infants and toddlers, some of whom debuted later in the series. Chuckie, Tommy's bespectacled, red-headed, insecure, cowardly two-year-old best friend; the twins Phil and Lil, noted for their revolting eccentricities and love of digging for and eating insects and earthworms; Tommy's baby brother Dil (who was born in "The Rugrats Movie"); Angelica, Tommy and Dil's outrageously spoiled and selfish three-year-old cousin who is a "rival" of his friends and the main antagonist of the program; Kimi, Chuckie's adventurous, playful stepsister (introduced in "Rugrats in Paris") (later just his sister after adoption); and Susie, a good-hearted neighbor of the Pickles family, Angelica's schoolmate, friend, and "rival", who is better liked by the younger children and far more reliable than Angelica.