Nellie's rancor was born, angry and squalling, from ten thousand things: the sensible shoes her mother made her wear in first grade when all the other girls wore sparkly sandals, the scar on her right cheek from the car accident she had in college, the strangers who'd stared, the jobs she didn't get and the jobs she'd never dreamed she could have, the loves she'd lost and been forgotten by, even the dingy walls of her tiny apartment. She picked it up and held it to her breast and determined to love it always, for it was hers.

In the mornings, Nellie woke her rancor up and fed it bitter gall and wormwood. After breakfast, she would take it to the park for some fresh air. For lunch she fed it grilled cheese sandwiches, charred well on both sides. In the afternoons her rancor napped while Nellie did her chores. For dinner her rancor dined upon curdled milk and rotten eggs. At night it slept uneasily, and often woke Nellie when its nightmares made it shriek.

Edited to add: there is one sentence that contains offensive language.

Edited to add: Um...We do all know that "rancor" is noun which means bitter resentment, usually over a long period of time, right? This is about emotion, not a bizarre SF animal.

I owe -- what -- a half-dozen crits or so? Looking forward to returning the favor.