Lucius Malfoy had just finished his errands (Death Eater related, of course), and had just arrived at the manor when the house elf taking his cloak had informed him of a visitor awaiting him in the lounge.
Lucius let the elf take his gloves and pushed open the door to the lounge. Sitting in one of the nicer silk upholstered high-backed chairs by the fire was none other than Severus Snape. He had obviously been waiting for at least a half hour, for he looked quite lost in whatever disturbing thought inhabited that greasy head of his.
"Hello Severus. I hope you are comfortable?" Lucius said, making Severus start. He would try and play it smooth, because he knew what was coming.
"Well, Lucius. I am comfortable. Thank you so much for being concerned on my behalf," Severus said very politely. He got up and stood closer to the fire.
To Lucius, this was unexpected. What he had expected was for Severus to start raging about the little trick he had been the victim of. The day after Lucius had turned every pair of Severus' shoes hot pink and glittery, which he knew would get him riled up, it had spread through the school like wildfire, thanks to Peeves. He even had a song and dance routine to match the pink glittery outfit (and shoes) he now sported. Even though Severus had changed all his shoes back, the ridicule had not died down.
For Severus to be acting as though nothing had happened was far from what Lucius had been preparing to face. He didn't like it one bit: it portended something worse to come. And he was scared.
While Lucius was silently sweating in his chair, Severus kept talking away. When Severus left and still nothing had happened, Lucius, instead of being relieved, got more nervous. He spent the rest of the day checking the house for booby traps. Severus was, after all, entirely alone before Lucius had arrived. Who knows what kind of horror he could have managed when he was gone?
At last comforted that Severus had not, in fact, rigged the house, Lucius went to bed that night and slept peacefully, with his wife already snoring at his side.
Lucius rolled over and a thought came into his mind: Narcissa doesn't snore. Come to think of it, she doesn't even sleep in this bed!
He scrambled out of the bed and the creature awoke with a snort. It got up slowly and turned its massive head at Lucius and uttered its battle cry.
What Severus saw that night, waiting just outside a window on the ground level, was forever imprinted in his mind: Lucius running like a maniac from the below village's prize 600-pound pig, rather fittingly named Monster.
Now it was Severus' turn to laugh into the night, and he walked into the shadows with a good story for Peeves when he got backto Hogwarts.