It's very rough. Vignette so far.
She found the hand cowering behind the dresser, curled into a tight little fist. At first, she’d thought it was a remarkably lifelike model left behind by a forgetful Sculpting major last semester. She’d tried to fish it out with a pencil, but when she poked it, it had unfurled and skittered under the bed. She was eventually able to coax it out by placing her own hand (thankfully still attached to her arm) palm-up on the floor and wiggling her fingers at it. It had taken three hours to get it to even touch her fingertips, but it had been worth it—no other girl in the dorm had a disembodied hand for a pet.
She’d had to buy another cage for it; her rats had freaked out when she’d put it into their cage. Now, it tapped idle rhythms on the sides of the glass, or traced lazy lopsided circles in the lotion she had squirted into a dish for it. She’d assumed it didn’t need to eat, as it had no mouth. She’d only had to trim its nails once. She had let them grow long, and when she reached into the cage to pet it, it had scrabbled at her hand and torn a gash in her index palm. After that, she’d put a small block of wood into the cage for it to scratch.
Her roommate didn’t mind the hand, saying that at least it didn’t smell or have babies the way her other pets did. She’d wanted to paint its nails pink. During room inspections, they had to hide it in the closet or under the bed, but it never seemed to disturb the hand any. It was as comfortable in the dark as it was in light.
She never wondered whose hand it had been. It was hers now, and that was all that mattered.