Mopsy Fleabert

Mopsy was a planned character for Harry Potter and the Goblet of Fire. She was cut because, in J.K. Rowling's words, she "added nothing to the plot."

Biography
Mopsy would have been an eccentric elderly witch who lived at the edge of Hogsmeade. She would have been especially fond of dogs, and would have kept several, much to the chagrin of her neighbours. One of the "strays" Mopsy would have taken in would have been a large, black dog who was truly the wizard Sirius Black in animagus form.

J.K. Rowling
J.K. Rowling has stated that she initially wished to include a dog-lover in the story to contrast with the cat-loving Arabella Figg. However, Rowling's editor asked her to cut Mopsy out of an early draft of Harry Potter and the Goblet of Fire. Rowling chose to have fugitive Sirius stay inside a cave instead, where he could freely discuss important matters with Harry, Ron, and Hermione without Mopsy's interference.