Dobby

Dobby is a house-elf who once served the Malfoy family. In Harry Potter and the Chamber of Secrets, he made several attempts to stop Harry Potter from returning to Hogwarts to try to keep him out of danger, nearly killing him in the process. Harry tricked Lucius Malfoy into giving Dobby a sock near the end of the book, thereby freeing Dobby. Dobby then went to work at Hogwarts, where he is the only elf who receives payment for his work.

Dobby has assisted Harry several times during the series. In Goblet of Fire, he gave Harry gillyweed to enable him to breathe underwater and rescue Ron Weasley in the second task of the Triwizard Tournament. In Order of the Phoenix, he told Harry about the Room of Requirement. In Half-Blood Prince, he and Kreacher tailed Draco Malfoy on Harry's orders.