Dr. Ritter waited patiently in quiet, thinly-veiled disgust as His Imperial Majesty Emperor Maximillian the Great greedily shovelled his meal down his cavernous gullet. Dr. Ritter had secretly harboured the hope that the reckless speed at which King Max (as the staff had taken to calling him) ate and the rarity with which he bothered to use his enormous, supernumerary teeth would eventually result in him choking to death, but so far there had been no such luck. Dr. Ritter supposed that if the creature's horrid table manners hadn't gotten him killed yet, then his anatomy was probably sufficiently non-human to render choking a moot concern.
Despite his scientific training and years of experience with the Foundation, Dr. Ritter was unable to view his assigned subject objectively. When he sat across from the bloated form of King Max, he saw only a monster from a fairy-tale. Not a modern, Disneyfied fairy-tale either, but an old European fairy-tale where children were eaten alive and not all villains got what they deserved.
At roughly 3600 pounds, Max was over two and a half times the weight of the heaviest human on record, coming closer to the size of an adult male hippopotamus. It took 54 000 calories a day to maintain that size, and the Foundation was more than willing to oblige him.
It was considered likely that he knew the locations of other SCP-3288 hives, which the Foundation desperately needed to prevent his kin from eventually overrunning the planet. Torture had proven ineffective, as it often did, so they decided it would be best to try a more hospitable approach, providing their royal guests with any and all reasonable requests.
They had dressed him (more for the comfort of the staff than for his own dignity) in a modified caparison that had originally been meant for a horse. They had let him keep his crown since the carbuncular outgrowths of flesh holding it in place meant that it could not be safely removed without surgery. They even gave him a throne, of sorts, having placed his immobile body over a hole in the floor that led straight to his personal septic tank. This too was more out of necessity than courtesy, as both the volume and vehemence of the King's imperial stool was beyond the ken of ordinary plumbing.
Food, however, was always King Max's most pertinent demand. In spite of his pretensions of nobility, he proved to not be a very picky eater. The bulk of his diet now consisted of rice, oats, and pasta supplemented by cafeteria leftovers that had past their use-by date. With a robust immune system and stomach acid as strong as a crocodile's, there was very little the corpulent king could not stomach.
And stomach it he did. Seventy pounds of it a day, enough to feed some people for a month. Though most of his fare was either cheap or rotten, his majesty did have one particular addiction for which no substitutions could be made, and the Foundation was forced to cater to it if they wanted his co-operation.
Each and every day, King Max reminded the Foundation why they had dubbed his species Homo anthropophagus. A literal pound of flesh, often from D-class who had died in the line of duty and whose corpses the Foundation had no better use for, was presented to the King as his reward for ‘good behaviour'.
It sickened Dr. Ritter. All of it. He tried to push those thoughts to the back of his mind, console himself with how many lives they could save if they could finally get this monster to disclose the location of the other hives, but it didn't work.
This abomination had been gorging itself to superhuman obesity on innocent children for over half a century before they had found it, and now that it was in containment they were still giving it human flesh? Weren't those D-class more human than this thing was? Didn't they deserve better? Didn't this bastard deserve worse?
Dr. Ritter showed little sign of his inner turmoil, merely pushing up his glasses and clearing his throat before he began the interrogation.
“Does His Imperial Majesty find himself in the mood for some after dinner conversation? I'd very much like to hear more about The Empress of the Black Forest.”
“Ah, The Empress. Magnificent creature, most noble of us all,” Max mused as he wiped his face with his now filthy caparison. “I had the privilege of seeing her before I swallowed my eyes, you know. More than ten feet tall she was, yet slender as a sapling. One eye pale blue, the other moonlit silver. Vanity's her greatest vice; has a vast collection of wigs made from the scalps of her prey. Not that she's ever let her femininity keep her from carnality. She delights in the violation of others; men and women, nobles and peasants, it's all the same to her. I made the mistake of scoffing when she said she could rape a man, and my poor anus hasn't been the same since.”
King Max tossed his head back in rancorous laughter.
“If I hadn't been both impeded and impotent from my girth, I'd've paid her back in kind, rest assured.”
“That's -” Dr. Ritter stopped to swallow the lump in his throat. “That's most fascinating your majesty. I'd very much like to meet her for myself someday. I assume her manor is in the Black Forest Mountains. Do you happen to know where exactly?”
Max chuckled deeply at the question.
“The Ruling Class does need to keep in touch with one another, of course. But I'm afraid my living arrangements, decent enough though they are, are not yet quite decadent enough for me to betray my fellow Royals.”
Dr. Ritter sighed, a feeling of dread welling up inside him.
“What more do you want?”
“Live meat, of course. Right now, I'm lucky if it's even fresh. I want something to play with, something that puts up a bit more of a fight. A child of four or five years once a fortnight. That won't empty your orphanages, surely? I'll settle for cripples. Practically doing you a favour.”
“I'll…” Dr. Ritter began.
I'll see what I can do. That's what he was supposed to say to the King's demands, no matter how obscene. He was to report all the brute's requests to his superiors, and they would decide with their coldly utilitarian rationality whether or not feeding this thing live children would be worth it.
And what if they said yes?
“I'll… I'll see you in the ground before I feed you children, you monster!” he shouted, slamming his fist on the button to activate the UV flood lamps that had been placed to subdue the King should he ever become hostile. Max howled in agony and terror as the light instantly burned his unpigmented skin. Dr. Ritter grabbed the caparison and yanked it off him, maximizing the King's exposure to the abhorred light.
“You tell me where the other hives are now, or I will burn you to a cinder you fat fuck!”
As with all previous attempts at torture, the King just screamed and pleaded for mercy.
“Dr. Ritter, you are not authorized to use enhanced interrogation on the subject,” a voice chastised him over the intercom. “Desist immediately, or you will be removed by force and subjected to disciplinary measures.”
It was nice of them to give him a warning. Not smart though. He jammed the door shut with his chair to buy himself a little extra time.
“Now I'm finally going to see you choke!”
He picked up the sheet the creature had been wearing and rapidly tied it into a crude noose. Then he placed it around King Max's neck, and pulled. Bracing his feet against the nearest fixture for leverage, he strangled the monster with all his might.
Max gargled as his airway was forced closed. He clawed at the noose with his stubby fingers, but couldn't get a grip. Security was banging at the door from the outside, trying to force their way in. It would only take them seconds, and Dr. Ritter needed minutes. Nonetheless, he would not stop pulling on the noose.
When the door slammed opened and the guards tackled him to the ground, he knew it hadn't been long enough for Max to suffocate. He despaired for a moment, fearing he had thrown his career away for nothing, until he heard the guard inspecting Max curse in frustration.
“Goddammit, it's dead!”
“What do you mean it's dead?”
“Its heart gave out. Too much stress for it, I guess.”
A wave of relief washed over Dr. Ritter. Even as he was dragged from the cell in handcuffs, a victorious grin spread across his face.

“Dr. Ritter, you have been brought before this disciplinary committee for the unauthorized termination of SCP-3288-Alpha,” the committee head said sternly, looking and sounding like the headmistress of a boarding school. “Due to SCP-3288-Alpha's authority and status among SCP-3288, it's likely your actions have cost the Foundation a rare and possibly unique source of strategic intelligence regarding a potential SK level threat to human society. Do you understand these charges?”
“I know exactly what I've done,” Dr. Ritter said, standing proud and without a hint of remorse in his voice. Whatever their practical reasons for indulging the creature had been, the moral absolutism in Dr. Ritter's own conscience had finally won out. When before his conscience had hardly let him sleep, it now told him that the countless people killed to feed King Max were avenged, that no more innocent lives would be sacrificed to the horrid people-eater, that Max had been a monstrously evil fairy-tale villain, and that made him the hero.
“I slayed the Goblin King.”