Dobby is an endearing character who is the Malfoys house elf. He begins by trying to prevent Harry from remaining at Hogwarts, but later on Harry manages to trick Malfoy into giving Dobby a sock which frees him.  'Master has given Dobby a sock? Dobby is a free elf!'  Dobby goes on to become a staunch ally to Harry eventually giving his life to save Harry and friends.