Scorpius held his breath, as he stood before the caged Dementor. Professor Longbottom watched him carefully, holding his own patronus steady. Then, with a nod, he let it fade, and Scorpius had to try to form his own.
He moved the wand as he had been taught, and searched desperately for a happy memory. "Expecto Patronum!"
As he saw the shape his Patronus had taken, he closed his eyes in disbelief. Around him, there were mutters from other students, with a few giggles from those who were muggle-born.
He'd chosen a time from his childhood as a happy memory. His parents had employed a muggle-born witch as a housekeeper, and when he was about four, she'd taken him out into the city surrounding the Malfoy estate. It was an area his parents had never allowed him access to, and he remembered how fascinated he'd been, how he'd spent almost half an hour riding a set of escalators up and down before she'd made him move on.
He'd been quizzing her as to how they worked without magic when she'd shown them to him. Statues, scattered around the city, all with the same shape, but with a variety of designs, each unique. She'd lifted him up, and let him sit on one, pretending to ride it. There was still a photo of that, somewhere at home.
She'd told him a story about the statues, one that she'd made up, about how they would come to life if the city were ever in danger, and rush to protect it.
His patronus had taken the shape of those creatures, and now it was prancing around the Dementor, singing the song he'd made up as a child, in a voice like tinkling bells.
"Lambanana, lambanana, lambanana..."
END
AN - Yes, Scorpius' patronus is a lambanana, the statues you can find scattered around Liverpool. Google image search it, they're adorable.
Malfoy manor is, canonically, in Wiltshire, but this is an AU where it's in Liverpool. Because, why not?