"These are leprechaun galleons," Fred whispered to Lee.
"They'll disappear in appear in a few hours. Fred and I put a Permanent Sticking Charm on them," George said in a low whisper. They were hiding behind suits of armor, waiting for their first victim.
"Percy's the first to see them!" Fred exclaimed in an excited whisper. Lee and George tried to stifle their laughs.
Percy approached the galleons and tried to pick them off the floor. The more he pulled on those galleons, the more Fred, George and Lee found it harder to not laugh.
Deciding his dignity was more important, Percy stood up, puffed his chest out so that his badge showed and moved on.
Fred snorted. "Idiot," George mumbled, and Lee stifled a laugh.
"Filch saw the coins!" Lee said. They all cowered behind the suits of armor.
Filch approached and repeated Percy's process minus the part of showing off of the badge.
After Filch left, Mrs. Norris trailed behind. George stumbled, and the suit of armor crashed. The cat ran off to find Filch.
"RUN!" Fred yelled.