Greg had had a litany of 'Coffee, coffee, coffee, coffee' dominating his mind and thus the sudden exclamation and pronouncement of 'Nifflers' left him baffled and staring at Ari in confusion.
"Uh, nifflers?" he said, trying to get his brain into gear. "Uh, black, fluffy, long-snouts, burrow in the ground, like shiny things?" His brain started to catch up at this point and he frowned slightly. "You have a niffler problem?"
Had one of the students bought one and left it in the castle? He wouldn't put it past a few of them. There always seemed to be at least two or three students each year who wanted to try and live up to the legends of Fred and George Weasley. As someone who seen the real deal, Greg could safely say no one had gotten close so far.