I really wasn't sure whether or not to do this one, but I decided it was cute and it worked.
"Harry…Potter…" Dobby's eyes fluttered, and then closed.
The pain in his stomach subsided, and a moment later, he found himself at Hogwarts, in the Hospital Wing. In fact, he recognized it: this was where he had spoken to Harry Potter back so many years ago after Dobby had cursed a Bludger after him.
"Dobby?" said a voice.
Dobby sprung up and looked around. His eyes fell on a man who he recognized vaguely…the fair hair, the grey eyes, the arrogant stance…
"You is Sirius Black!" He exclaimed finally.
Sirius chuckled. "Yes, I'm Sirius. Nice to meet you officially. Harry spoke highly of you and I—"
"Harry Potter spoke highly of Dobby?" The elf's eyes watered with tears. "Dobby did not know this, Master Black. It makes Dobby most happy."
Sirius grinned again. "He did, and often. I just…well I wanted to thank you for the help you've given him over the years." He paused. "And I wanted to thank you for keeping Kreacher in check."
Dobby grinned. "Thank yous, Master Black!"
"Call me Sirius, please."