The babies in Rugrats are illusions of what they all could have been- they don't exist and are products of Angelica's demented imagination. Her mother ignores her and her relationship with her father is shallow and parasitic. In reality, Chuckie died along with his mother, which is why Chaz is such a nervous wreck. Tommy was a stillborn, which causes Stu to sit in the basement making toys for his son that never had a chance to live, and the DeVilles had an abortion. Angelica couldn't decide whether the unborn child would be male or female and thus simply invented the same character in her head twice with different genders… or maybe not.