Bubbles is a My Little Pony: Friendship Is Magic oneshot. The writer is anonymous, but the story was written early in the fandom's lifespan.
The story is about the foalhood of a background pony referred to by most as "Derpy Hooves". Derpy is ignorant to the fact she's considered different from other foals. Her mother, on the other hand, is well-aware of her daughter's disabilities and hates her for it. Derpy doesn't care though—she's ignorant to the harshness of her home life.
Bubbles provides examples of:
- Abandon the Disabled: Derpy is abandoned in the woods by her mother at the end of the story.
- Abusive Parents: Derpy's mother is emotionally and physically abusive. It's also implied that she tried to poison her and then she abandons Derpy in the woods.
- Ambiguous Disorder:
- Derpy is meant to have a mental/neurological/developmental disability, but nothing is specified in the narrative. She might also have physical issues as it's noted that she has difficulties controlling her body movements, she can't speak well, and she can't see well (due to her lazy eye).
- It's mentioned that Derpy's mother is on medicine that makes her "stop crying" when she's depressed.
- Bittersweet Ending: The story ends with Derpy being abandoned in the woods. The only thing making this a "Bittersweet Ending" and not a straight up Downer Ending is that it's about an established character's childhood, so obviously she ended up fine in the end.
- Friendless Background: Derpy is kept inside most of the time and doesn't have any friends her age.
- Offing the Offspring: It's implied that Derpy's mother tried to poison her, but it didn't work.
- Parental Abandonment: The fic ends in Derpy being abandoned in a forest by her mother.
- Parental Neglect: Derpy's mother does the bare minimum to take care of her and prefers to avoid her.
- Potty Failure: On her first (and apparently only) day of school, Derpy had an accident. It's implied she was laughed at by the other kids, but she doesn't take much notice to it.
- Third-Person Person: The fic is told from a first person POV but Derpy refers to herself by her name.
- Unfortunate Names: Derpy's name is often deemed negative. In the context of the story, it makes sense that her abusive mother would give her a demeaning name.