Prompt: Fed up with how irritating and power-hungry she is, Professor Snape slips a poison into Dolores Umbridge's morning pumpkin juice. Unfortunately, he grabbed the wrong vial and, instead, the potion turns her into a llama.
He couldn't take it anymore.
In between spying for Voldemort, spying for Dumbledore, spying on Harry Potter, and spying for something to eat away from irritating dunderheads, Professor Snape now had to deal with this... toad.
There was no other way to describe her without violating the quite liberal Hogwarts' Staff Code of Conduct. Due to his life experiences, he had quite a list of insults, epithets, put-downs and insults to use just for her. The fact that he thought of 'insults' twice merely highlighted his facility with that brand of communication. Where Umbridge was concerned, he could very easily shift into the rarely-used fifth level range of insults but the sad thing was... she'd never realize she was being insulted.
The monitoring of the Defense classes was an insult to him personally. He never thought he would agree with a Potter, even the Potter that he sworn on his mother's corpse to protect. That was rough enough on his pride but this - this was far too much.
He wasn't Dumbledore. Merlin help him if he got that batty.
His lips creased infinitesimally at the mental wordplay, amused. The Dungeon Bat of Hogwarts calling someone batty. Several students saw the emotion on his face and ran frantically, screaming bloody murder the whole way. Professor Snape took the sudden silence as a good thing, as he was gifted an opportunity out of the blue to do something he had been pondering.
There was a 'special mixture' that he had awaiting his use. Snape had to stop and think for a moment about which one, since he had by now ten or twenty 'special mixtures,' for several different uses. Some of the 'special mixtures' could be combined for different results. Being a Potions Master had its advantages, of course. He was the best bartender Hogwarts had seen in decades, for instance - not that he advertised that. The Weasley Twins had nothing on him. Granted, they had loads of innovation in their potions works and also granted, he had contributed a thing or twelve to their exploits, but this new problem was something that he wouldn't farm out to their special brand of chaos.
No, he was a Death Eater (retired) for a reason.
Cursing the low light levels in the dungeons that Albus frickin' Dumbledore refused to do something about, Snape grabbed a vial and swept off to the Great Hall for breakfast. He was going to take care of Dolores 'Toady' Umbridge today and sleep well tonight. This particular brew, when consumed, would make all nerve impulses misfire into random points all over the body until suddenly pouring every bit of the body's energy into every nerve ending while making the heart race. It was odorless, tasteless, dissolved instantly in liquid and Snape had made it to be among the more deadly poisons known to wizardkind. In fact, it was derived from an Australian poison that he had to be very careful with.
It was child's play, really. Dolores was too busy looking self-important to notice what he was doing. A simple switching spell, performed wandlessly and silently, replaced a volume of her pumpkin juice equivalent to what was in the vial. Snape was done with Dolores Umbridge, and he looked forward to watching her croak.
Another miniscule smirk crossed his face and the students who noticed immediately lost their appetites for the rest of the day. Some vomited what little bit they had already eaten in fear and found themselves carted off to Madam Pomfrey's den of torture. They didn't argue, seeing being there instead of the Great Hall as a distinct upside to their day. The ones who hadn't noticed wondered if they should be eating breakfast or lunch.
Later, the Hogwarts house elves would run themselves ragged trying to figure out what was wrong with the food.
Meanwhile, Professor Snape waited to see the results. The anticipation was keen within him, the brilliant mind screaming for her to shut the hell up and just drink while his face didn't react. There were too many slights and insults made whole by her very presence, and he, Professor Severus Snape, had had far enough.
Finally, she did.
He watched as the pumpkin juice was gulped down, the malignity in the liquid coursing through her body even as he started to partake of his own breakfast.
The first sign was the beads of sweat popping out on her brow. He heard her inane comments about the Great Hall seeming to be warmer than usual, which was unusual in itself thanks to the position in the Scottish Highlands.
The second sign was the slight laboring to her respirations, which he could detect easily. As a Potions Master, he had to have current mediwizard certifications. Madam Pomfrey could have seen this too, but unfortunately for some reason she was occupied with dunderheads that had suddenly taken ill.
Pity.
The third sign was the hacking coughs that heralded the imminence of what he'd put into play and the ineluctability of the process. There was no way to stop it now, he knew, and he took another bite as others rushed to her.
Soon. Soon revenge would be his, and he carefully dabbed his lips as he got up. Professor Snape walked over to lend credence to the appearance that he was here to help the benighted High Inquisitor. He reached into his pocket and pulled out a potion of his own creation that would 'heal' the problems in 'most' cases. Too bad it wasn't going to work with his 'special mixture.' Instead, it would amplify the effects. He poured it down her gagging throat with less-than-gentle efforts and sat back. The expression on his face told the most artful tale that he was waiting for the potion to work, and she would soon be put to rights.
Instead, he watched with disbelief as Umbridge transformed most painfully into a llama.
The ugliest, most bad-tempered, stout and bowlegged llama he'd ever seen in his life.
Instantly, his mind went back to the vial he'd picked up. Those damn dim lights had made him mistake one vial for another. Dumbledore's desire to cut costs or preserve the ambience, he never knew which, had contributed. He thought about the second vial and realized that there was no way for the process to be reverted. Both potions were undetectable and unfilterable in blood tests. No one knew that he possessed the first, and he'd used the second without problems for years. There was no way to trace it back to him, and he thought that maybe this worked out well after all.
Umbridge would remain a llama for the rest of her life. She seemed to know it, too, if the braying and spitting meant anything.
He smirked again and Madam Pomfrey had more cases to see too, thinking that the fright of the events had caused the issues. Classes were canceled for the day, and Professor Snape escaped to the peace and quiet of his dungeons away from the dunderheads.