Crookshanks is Hermione Granger's pet cat, who appears in LEGO Harry Potter: Years 1-4. In the Harry Potter storyline, he is part kneazle, an intelligent cat. He knew Ron Weasley's pet rat Scabbers, was actually Peter Pettigrew in disguise. He assisted Sirius Black in capturing Peter. Crookshanks found out how to enter the Whomping Willow (by poking the knot with his tail). In LEGO Harry Potter: Years 1-4, in and after the 3rd year, Hermione can send Crookshanks into tubes. He also appears in LEGO Harry Potter: Years 5-7, once again as Hermione Granger's pet cat.