I Built a Divine Zoo in Another World

The ground trembled.

Not because of the horde still charging toward the Rat King. Not because of the monsters crashing against the soldiers’ formation.

The tremor came from something far deeper, something that made the very earth groan beneath the weight of an energy that should not exist in this world.

From the absurd amount of mana gathering before them.

Lukas felt every fiber of his body vibrate in resonance with that energy. It was as though the air had become solid, heavy, and difficult to breathe. Every breath brought not only air into his lungs but also a crushing pressure that seemed intent on forcing him into the ground.

Thousands of rats continued running toward the Rat King. Not one of them slowed down. Not one showed fear.

Their red eyes glowed with an almost hypnotic intensity, and their bodies moved with a determination that transcended the instinct for survival. It was as if each of them were part of a single organism, cells of a greater body being called back to their origin.

The moment they reached the creature’s enormous body, they simply disappeared. There were no screams. There was no pain. Only absolute silence as their forms dissolved into the darkness surrounding the King.

They were absorbed.

Their bodies dissolved into a black mass that merged with the King’s flesh, like rivers flowing into a bottomless ocean. The dark matter streamed across the creature’s surface, absorbed through its skin like water soaking into a sponge.

Each newly absorbed rat added its mass to that growing monstrosity, contributing to something none of them could possibly comprehend.

With every new rat absorbed... the creature grew.

The plates covering its body slowly expanded, producing deep cracking sounds that echoed throughout the forest. The noise resembled ancient trees splitting apart or massive stones being crushed by an impossible force.

’CRAAACK...’

New limbs began to emerge beneath its skin. At first, they were only small bulges moving as though they had lives of their own. Then they became more defined, arms, legs, appendages that belonged to no known creature.

The flesh stretched and warped, reshaping itself into forms that defied natural anatomy.

Tails multiplied. Where there had once been dozens, there were now hundreds. Each moved with a will of its own, lashing through the air in chaotic patterns that seemed to follow some hidden logic.

The countless eyes scattered across its back opened and closed erratically, as though every newly absorbed rat added another gaze to that monstrosity.

Some were open, others closed, while others quivered as though on the verge of bursting. Yet all of them stared in the same direction, toward the group of humans preparing to face it.

The black mana became visible.

Columns of corrupted energy rose around the King, slowly revolving like an enormous dark hurricane. Each pillar was several meters wide and stretched into the sky, where it dispersed into a haze that blocked out the sunlight.

The surrounding forest was plunged into an artificial darkness, as though even the light itself had chosen to retreat before that abomination.

The nearby trees began to rot. Their leaves withered within seconds, their vibrant green fading to brown, then black, before crumbling into dust.

Their trunks shriveled, cracked, and bent, as though they had aged a thousand years in mere moments.

The grass darkened. The vibrant green carpet covering the clearing gave way to dull gray, then black, then nothing at all. Bare earth was exposed beneath, cracked and barren.

Even the stones seemed to lose their color. The gray of the rocks turned pale, then white, before finally crumbling into fine sand that the wind carried away.

It was as though life itself were being drained from that place. Every inch of soil, every leaf, every living thing that came too close to that energy had its essence siphoned away to fuel the King’s transformation.

The wind mage’s eyes widened. His mouth opened, but no sound came out for a long moment. He tried to speak several times before his voice finally emerged.

”...Impossible.”

The word came out almost as a whisper, so quiet that only the nearest soldiers could hear it. Yet the tone in which it was spoken, a mixture of disbelief and terror, was enough to make several of them shudder.

That was not an amount of mana an ordinary monster could possess.

Even the Rank A monsters he had encountered during his travels, those living legends among hunters, could not compare to what he was witnessing.

The energy radiating from the Rat King was of a magnitude that defied his understanding.

Beside him, the support mage felt the same thing. Her face, which had regained some color after resting, lost every trace of it.

She gripped her staff so tightly that her fingers turned completely white, the joints standing out beneath her skin.

”Corrupted... mana...”

Her breathing quickened, and tiny beads of sweat began to run down her forehead. She was sensitive to mana in a way the others were not, and what she felt now was like plunging into an ocean of poison.

”I’ve never... never felt anything this dense...”

Even from hundreds of meters away, that energy seemed to suffocate her senses. It was as though she were wrapped in a soaking wet blanket, heavy and tightening around her body, preventing her lungs from fully expanding.

It was heavy. Viscous. As though the very air itself had been contaminated, transformed into something that should never be breathed.

Lukas felt it as well.

But it was different.

It wasn’t only the pressure of the mana affecting him. It wasn’t merely the weight of the corrupted energy or the sensation of being watched by hundreds of eyes.

It was fear.

His entire body trembled. It wasn’t the kind of trembling that could be suppressed through willpower. It was a deep, visceral shaking that rose from the core of his being and spread through every muscle, every bone, and every fiber of his body.

His legs felt as though they were made of lead. Every movement demanded a monumental effort, as if he were trying to walk through mud up to his neck.

His heart pounded so violently that it hurt. Every beat echoed in his ears like a drum, drowning out the other sounds around him. His peripheral vision began to darken, and he had to force himself to blink repeatedly just to stay focused.

That creature... was incomparably superior to anything he had ever seen. Even the Royal Guards, who had seemed so terrifying when they first appeared, now looked insignificant compared to what the Rat King was becoming.

Even Clavor... Even Count Hark... Even together...

Would that be enough?

For the first time since the battle had begun, doubt crept into his mind. It wasn’t a fleeting doubt, the kind that comes and goes like clouds drifting across the sky. It was a cold, crushing certainty that settled in his chest like a stone.

’Can they really win...?’