Melissa Mielfée and the Omphalonian Orchid is a Harry Potter x Charlie and the Chocolate Factory crossover fanfic in ten songs.
I am (and you should be) completely done with Harry Potter as a commercial franchise, due to the author's ongoing vocal transphobia. If you're also completely done with HP as a fandom, obviously skip this one. Roald Dahl was also not an unproblematic author. Both authors included problematically stereotyped servile diminutive races in their worlds, which this fanfic calls out and attempts to correct.