Percy looked at the glass flask in his hand, eying the Polyjuice with a critical look. If he'd been the one brewing it, it mightn't have mattered so much, but this was something that had been delivered to him by Mundungus Fletcher, and that alone was enough to make Percy suspicious. Fortunately, it looked like Polyjuice, and it even smelled like Polyjuice.
He swirled it around and then looked at Penny, who was currently dressed in an old pair of his robes and holding a pair of spectacles that he'd duplicated with a spell. He felt a swell of fondness for her, dressed that way, in his clothes. Enough fondness to make him forget the fact that she would be walking around in his body - which was still mildly horrifying.
"All right," he said, and with a wince, pulled a ginger hair from his scalp. "Penny, I apologize for however bad this may taste." He was deliberately avoiding the topic of how much he'd miss her, and how much he ached, knowing that she would be leaving and putting herself at risk.
Dropping his hair into the potion, he drew his brows together as it turned cranberry red. At least it didn't look too off-putting.