Disclaimer- I don't own anything you can recognize.
Harry opened the window and laid down, knowing that any bird would wake him. It wasn't ten minutes later that the first owl with a present came through- it was from the Weasley's, with his normal fudge and candy and trinkets. The next was Hermione's...which you can never guess...a book.
The surprise came with the boxes after the normal ones.
As you have equipped me for being a Dark Lord, so I must equip you to be a superhero. Inside you will find a portkey to your headquarters, a lovely place with an even lovelier view. I'm sure you'll spend all day there so that I can provide the last of your present while you are gone.
The next box started whimpering, and Harry opened it to find a Mankh, one of the most loyal creatures around. While I may have a stereotypical animal, Heroes do not. All that is known is that they are completely loyal. Thus you have a Mankh that will accompany you through your life loyally.
The third and last box held something that first made Harry puke, then made him grab some sunglasses.
I had help from the portrait of Albus Dumbledore to create this. If you don't like it, then I am sure you can change it to fit your style, but I'm sure you know that all heroes need a costume to protect their identity.
Harry blinked several times before turning the whole thing black, then putting electric green trim on it.
Everything was gathered up and put in his trunk, before he picked up the portkey and left, going to a fully stocked 'headquarters' that could also be termed a 'bachelor pad'.
His return several hours later was caught by several policemen there to discuss the death of his relatives, and that the house defaulted to him, because Marjorie Dursley was also dead.
The fact Harry didn't cheer must count for something.
As soon as they were gone, Harry dialled the number to Voldemort's cell, "Hello? Thank you for an interesting birthday."
"I killed your relatives, aren't you supposed to yell at me in grief at least once?"
"I'll think about it tomorrow. Right now I'm considering the bar at my Headquarters. Thank you for that, by the way."
Voldemort was surprised, and nodded before he realized that the phone wouldn't transfer that. "You're welcome."
"Ok. I'll see what I can do about Christmas, but I can't think of anything else to give a Dark Lord."
"..."
"Maybe I'll just send you a puffskein, they like being tortured...Ya know, I think that sounds like a rather good idea actually."