Alas, I am not J.K. Rowling and Harry Potter doesn't belong to me. I got over it.
***
Snape sank into an oversized bed in a random room at Number 12. He had stayed awake just long enough to reflect that he had had good reason never to eat or drink there, especially for a party. And what a party it had been! Snape drifted to sleep after his first meal ever at Headquarters…
***
"Harry! What the heck are you doing in my dream!" Snape roared. He really was quite drunk.
Grinning in just the way Snape hated, Harry replied, "But this isn't a dream."
"What do you mean, Potter?" Snape asked with a sneer, trying to regain his cold composure, "Surely a brain like yours," he smirked, "would draw the right conclusions, given that we are the only two people in a completely white nothing."
Harry looked as though he was restraining himself from saying, "who dreams of that?" in a sardonic voice. But he simply replied, "You're right, and you're dead."
"The darn cake!" Snape hissed. Why did he take it from Fred? It hadn't even looked safe.
"Apparently someone likes you, because they've allowed you to be reincarnated, but only as either a dog, or a chicken."
Thinking of Sirius, Snape chose to be chicken.
***
*poof* Snape the chicken was waddling around some random barnyard. He cursed, but heard only particularly vicious cluck. This prompted a very violent but completely silent tantrum, during which Snape learned of several body parts he had never known that chickens had.
He stopped this very un-Snape-like behavior only to reflect that the hangover had carried into his next life. It figured.
Suddenly, a tremendous pressure built up in his stomach and he decided to waddle into the hen house to lie down. Hygiene had never been exactly important to him, so he just picked any old flea-infested nest and sat down, sweating.
"Ooh, you must be the new hen," exclaimed an absolutely miniscule chicken from across the henhouse.
"Hen!" he sputtered, then onto more, well, pressing matters, he gestured to his stomach with a look of great pain.
"Oh that! You're ovulating. Just relax and let it pass."
He did. Despite himself, a large grin spread across Snape's face as he laid egg after egg, feeling better all the time.
***
"Blimey! Fred! You won't believe – " Someone was yelling.
A camera clicked.
"Wake up you old git, you've pooped the bed!"
The one consolation – George's nose will probably never be the same again.