Dobby has no master. Dobby is a free elf!

“He's a funny man, Dumbledore. I think he sort of wanted to give me a chance. I …”

“According to Madam Pomfrey, thoughts could leave deeper scars than almost anyth…”

“Oh, come on, Harry,” said Hermione, suddenly impatient. “It’s not Quidditch tha…”

“I WILL NOT TOLERATE MENTION OF YOUR ABNORMALITY UNDER THIS ROOF!”