The house-elf that serves the Malfoy family is Dobby. He is introduced as the Malfoys’ servant, but secretly tries to prevent Harry Potter from returning to Hogwarts because he knows that Lucius Malfoy is involved in a dangerous plan.
In Harry Potter and the Chamber of Secrets, Dobby interferes with Harry’s mail, blocks the barrier to Platform Nine and Three-Quarters, and uses a Bludger to keep Harry away from school. His actions are meant to protect Harry, although they repeatedly create trouble. Dobby later warns Harry about the Chamber of Secrets and helps him escape from the Malfoy family’s control.
Dobby is freed when Harry tricks Lucius into giving him a sock. House-elves become free when their owners give them clothing, so the sock ends Dobby’s enslavement. He later works at Hogwarts and becomes a loyal ally of Harry. Kreacher serves the Black family, while Winky serves the Crouches.