It was a few days after Voldemort and Harry had dueled with pranks and fell to the soul magic binding them. Both Lords of Magic along with their resident dour Potions Master, were sitting in the library reading or doing research. The gazes of both older men kept straying to check on Harry, but it was the Dark Lord's power filled gaze that carried so many things the dark wizard couldn't understand that frustrated the green eyed youth the most. Finally, he got fed up with trying to read and ignoring the looks both men kept giving him, especially Voldemort's, and met the gaze of the next one to look at him.
Voldemort was a bit taken aback by the myriad of frustration, annoyance, and mischievousness he saw in the emerald eyes that had suddenly decided to meet his gaze as he once more looked over at his counter-part. He felt the spell hit him but couldn't immediately tell what the effects were. However, judging from the increasingly amused expression on the green eyed brat's face and the laughter in his eyes, not to mention the sudden pain in his ass and at the crown of his head, he probably wouldn't like the results. With a minor sense of dread, he conjured a mirror and tried to figure out what had happened.
Voldemort's look of astonishment at discovering the white cat ears suddenly hidden within his hair and the increased tension in his body as he realized he had grown a rather long furred tail that was being painfully squashed underneath him was too much for Harry. The younger wizard let out a snicker and, when he saw the look on his counter-part's face, bolted from the room with the furious Dark Lord turned Neko on his heels. They left behind a rather amused Potions Master to watch as Harry fled from the ruby eyed Lord of Magic who was tossing more powerful retaliatory prank spells at the younger wizard.
"Potter!" Voldemort's roar of outrage had most of the house wondering exactly what Harry had done this time. More than half of them secretly hoped they could get the young wizard to teach them whatever prank he had done.
"You look good with cat ears!" Harry called back loudly, laughing as he quickly ducked around a corner to evade the return spell fire.
"Brat!" Voldemort yelled after him, as he ricocheted off a wall to avoid dropping speed while going around the corner, as he chased the green eyed menace. Finally, he managed to hit Harry in the back with a spell, sending the powerful young wizard tumbling down the hallway even as his clothing, skin, and hair changed.
When Harry finally rolled to a stop, he looked like a demented cross between a traditional muggle Christmas elf and an over loaded Christmas tree. As Harry got up, Voldemort could see that his second half twist during the last syllable of the spell had successfully caused Harry's eyes to start glowing brightly as if they were lights on the Christmas tree. A moment later, Ron and the twins rounded the corner in search of what had been causing all of the noise only to stop dead at the sight that Harry made. A smug white Neko version of Voldemort stood a few feet away, admiring his own work, while his fluffy white tail flicked back and forth playfully from beneath his robes.
It took a few moments for them to process what they were seeing but when they did, none of them could stop laughing for close to five minutes as Harry looked at them sourly. Voldemort, on the other hand, simply continued to admire his handy work smugly, with his white ears pricked up and aimed forwards with his tail swishing back and forth behind him, a self satisfied purr rumbling softly out of his chest.
"Brilliant!" Fred declared in gasps, as he tried to catch his breath while leaning against his still laughing brother.
"I never thought to mix those charms and transfiguration together," Ron agreed breathlessly. "That would have been perfect to pull on Malfoy or Zabini!"
"Hey, should we dress Professor Snape in a giant bat suit and a Santa hat to match them? Or just dress him up like Santa? Or better yet, a Master Vampire?" George asked gleefully, finally getting his own laughter under control.
"Severus is off limits," Voldemort said sternly, quickly cutting the idea off at the knees. "If he strikes and you can prove it then you can retaliate but I'm not risking our potions supply."
They all paused to think about that for a moment. The three redheaded pranksters reluctantly agreed that risking Snape's refusal or inability to brew was out of the question. They decided it would be unwise to point out the twins' own prowess in potion making, lest they be volunteered to take over until Snape has recovered from any pranks. The three Weasleys headed off to plot their own pranks and work on ideas that seeing Harry and Voldemort's additions had spawned. Just as they turned the corner to head back to their temporary prank lab, they heard two voices, one cast a spell and a moment later the other yelled, clearly responding to the result of the spell. The three Weasley boys looked at each other before they bolted to the relative safety of the twins' prank lab, trying very hard not to get caught in any potential cross-fire, as the two Lord of Magic engaged in yet another prank skirmish.