The Singing Valentine

All day long, the dwarfs kept barging into their classes to deliver valentines, to the annoyance of the teachers, and late that afternoon as the Gryffindors were walking upstairs for Charms, one of the dwarfs caught up with Harry.
"Oy, you! 'Arry Potter!" shouted a particularly grim-looking dwarf, elbowing people out of the way to get to Harry.
Hot all over at the thought of being given a valentine in front of a line of first years, which happened to include Ginny Weasley, Harry tried to escape. The dwarf, however, cut his way through the crowd by kicking people's shins, and reached him before he'd gone two paces.
"I've got a musical message to deliver to 'Arry Potter in person," he said, twanging his harp in a threatening sort of way.
"Not here," Harry hissed, trying to escape.
"Stay still!" grunted the dwarf, grabbing hold of Harry's bag and pulling him back.
"Let me go!" Harry snarled, tugging.
With a loud ripping noise, his bag split in two. His books, wand, parchment, and quill spilled onto the floor and his ink bottle smashed over everything.
Harry scrambled around, trying to pick it all up before the dwarf started singing, causing something of a holdup in the corridor.
"What's going on here?" came the cold, drawling voice of Draco Malfoy. Harry started stuffing everything feverishly into his ripped bag, desperate to get away before Malfoy could hear his musical valentine.
"What's all this commotion?" said another familiar voice as Percy Weasley arrived.
Losing his head, Harry tried to make a run for it, but the dwarf seized him around the knees and brought him crashing to the floor.
"Right," he said, sitting on Harry's ankles. "Here is your singing valentine:
"His eyes are as green as a fresh pickled toad,
His hair is as dark as a blackboard.
I wish he was mine, he's really divine,
The hero who conquered the Dark Lord."
***
Harry Potter and the Chamber of Secrets, Chapter Thirteen: The Very Secret Diary