Kreacher is often overlooked when fans of the Wizarding World list their favorite Harry Potter characters, but he is easily one of the more complex and important of the entire series. A stubborn, mean old house-elf by the time Harry Potter meets him, Kreacher is easy to look past despite his crucial history. Many fans of the series fail to acknowledge the importance of Kreacher in Harry's overall plight to restore peace to the magical world.
Source：https://www.cbr.com/harry-potter-kreacher-key-defeating-voldemort/
