Crookshanks : “The cat’s ginger fur was thick and fluffy, but it was definitely a bit bowlegged…” (PoA 60).
Mundungus : “He had short bandy legs, long straggly ginger hair…” (OotP 22).
Though Crookshanks is spunky and Mundungus is said to resemble a basset hound, there is no doubt that as a cat and a crook, respectively, they each live by their wits.
And, hello, Crookshanks is called Crookshanks and Mundungus is a crook.
Are they somehow more related??
cited:
Rowling, J. K.. Harry Potter and the Prisoner of Azkaban. New York, Toronto:, Aukland, Sydney, Mexico City, New Delhi, Hong Kong, Buenos Aires Scholastic Inc., 1999.
Rowling, J. K.. Harry Potter and the Order of the Phoenix. New York, Toronto:, Aukland, Sydney, Mexico City, New Delhi, Hong Kong, Buenos Aires Scholastic Inc., 1999.


