James and Sirius were disappointed when they saw the results of Peter's raid on the kitchens. "German sausage, Wormy?" James queried. "Is that all you could get?"
"Sorry, Prongs, the elves were busy making lunches for the OWL examiners and they chased me out before I could get at the good stuff," Pettigrew apologised.
"I'd like it in my Padfoot form," Sirius said, "but I'm not keen on it otherwise. Although…" he grinned, "I've an idea for using it in a prank."
The four Marauders set off in search of Snivellus and soon, with the aid of the Map, they tracked him down. A brief barrage of spells later and Snape was hanging upside down in mid-air, with his underwear showing, and without his wand. He shouted imprecations at his tormentors but they silenced him by stuffing sausage into his mouth.
"Who wants to see me take off Snivelly's pants?" asked James.
"No, Prongs," Sirius said. "I've a better idea."
With precise use of Wingardium Leviosa, the Marauders filled Snape's pants with German sausage, creating an impressive bulge.
Watching this in Snape's pensieve, years later, Harry was horrified and embarrassed.
He realised that he had just seen Snape's Wurst Memory.