One of the most heartwarming and unique tropes in 'Harry Potter' fanfiction is when Harry ends up calling Mrs. Black 'grandma'—it’s such a delightful twist on the Black family dynamics, especially given how notoriously grim that household is in canon. There’s this one fic, 'The Black Family’s Secret Guardian,' where Harry, after a series of magical mishaps, gets unofficially adopted by the portrait of Mrs. Black. The way the writer develops their relationship is so endearing; she starts off screeching insults, but over time, she softens into this grudgingly affectionate figure who secretly dotes on Harry. The dialogue is hilarious, with Harry cheekily calling her 'grandma' just to provoke her, only for her to eventually lean into the role. It’s a perfect blend of humor and found-family warmth.
Another gem is 'Grandmother’s Portrait,' where Harry discovers a way to interact with the portrait beyond her usual shouts. The fic explores the idea of Mrs. Black having hidden layers—maybe even regret—beneath her pure-blood mania. Harry’s persistent kindness chips away at her defenses, and the moment she finally accepts the 'grandma' title feels earned. The writer does a fantastic job balancing her canonical bitterness with gradual vulnerability. Plus, the reactions from other characters, especially Sirius, add so much depth. It’s one of those fics that makes you wish Rowling had given the Black family more nuance.
Then there’s 'A Portrait of Rebellion,' where Harry, fed up with the Dursleys, starts confiding in Mrs. Black’s portrait. Her initially harsh advice slowly morphs into genuine guidance, and their bond becomes a highlight of the story. The fic cleverly uses her portrait as a metaphor for legacy and change, with Harry’s influence helping her reconcile with her past. The 'grandma' nickname emerges organically, almost as an inside joke between them, and it’s just chef’s kiss. These fics all share a knack for turning a minor, antagonistic element into something unexpectedly touching. Makes me grin every time I reread them.