I have a Thestral action figure at home (Yes, I have an action figure, don't judge me) and this just came to me. It's a bit weird, but enjoy!
The sky is painted orange and streaked with pillows of cloud. A figure stands, alone, looking up at the sky with as much intensity as someone staring at a particular thing. From the door of the house in sight of the hill, Albus Potter emerges, carrying a large tawny owl on his shoulder. The owl is the figure on the hill's first clue to company, as it flies by with a grateful screech.
"Dad?" said Albus, panting after his trek up the hill.
"Hey Albus. What are you doing here?"
"I came to see what you're up to," replied Albus, watching the owl circling above his head. "And mum said I needed to take Firebolt out."
Harry smiled. "Was she nagging you much?"
Albus shrugged, and his dad returned to watching the sky.
"What are you looking at?" asked Albus eventually.
Without averting his eyes, Harry said, "Thestrals."
'You'll learn about them once you go to Hogwarts. They're like horses. Winged, skeletal, and slightly ugly horses. There's a whole herd of them over there," he pointed towards the clump of forest in the distance. Albus squinted his eyes; he couldn't see anything.
"But there's nothing there." said Albus.
Harry smiled again. An odd, emotionless smile. "You won't be able to see them, son. You can only see Thestrals if you've watched someone die."
"That isn't very nice," said Albus quietly. "Who have you watched die?"
"So many people," he paused, seeing the expression on his son's face. Harry ruffled Albus' hair. "You'll learn about that too, when you turn eleven."
Albus' expression didn't change. Harry took his eyes off the sky for the first time and bent down so he was face to face with Albus. "You're still worried, aren't you?"
Albus nodded. "It's scary."
"Well, didn't you find it hard too? Leaving your aunt and uncle's house for a whole school year?" asked Albus.
"Not at all. In fact, Hogwarts was more of a home to me than there. I promise, you're going to love it."
Albus didn't say anything else for a few minutes, after which he simply whispered, "Ok. I'll try."
Firebolt flew back and perched on Albus' shoulder. He ruffled the boys' hair affectionately. Harry took his hand and together they started back down the hill.
So, what did you think?
Disclaimer: I don't own Harry Potter; the lucky person responsible for that is J.K Rowling.