My Baby Doll

This trope is when a mother, in a delusion, thinks that a doll is her child. It can be caused by guilt due to Parental Abandonment, trauma or artificial means. But no matter the means, the result is that the mother treats a doll as her child. Whenever the real child interacts with his mother, she treats him as an impostor to take the place of her child, for added irony and sadness. The best case scenario is that the mother is so wrapped up that she doesn't even realize that her real child is standing in front of her and the mother thinks that the child is a stranger. It can involve The Doll Episode.

Artificial Humans and Replacement Goldfish are different, as the original child is still alive. Also, being a Living Doll Collector is not this.

Anime and Manga

 * The Ur Example is Kyoko Zeppelin Soryu from Neon Genesis Evangelion. After the contact experiment with Unit 02, this fractured her psyche and led to her belief that the doll was Asuka. However, due to her psychotic nature, she decapitated at least one of the dolls and then committed a 'murder-suicide' with another. A young Asuka was the first to discover such a scene.
 * In The Familiar of Zero,
 * In Tales of Symphonia,
 * Joy from Psychoville has a doll called "Freddie" that she is convinced is her real child. She even steals blood from the hospital where she works to give Freddie transfusions.