Nibiru is a Human

"So you can inflate?" she asked me.

I nodded. "Absolutely."

"Okay, but... how does it work?"

"I just breathe in." I demonstrated, the air swirling and filling me. My gut surged out, my backside and chest following immediately after. The armpits of my shirt grew snug on me as the denim of my jeans pulled taut across my legs, and mere seconds later I was a bulging, buoyant version of my old self. Not wanting to leave things half-finished I continued, arms and legs being forced apart before growing wider, then rounder, then being absorbed almost fully by my globular figure.

"Can you get bigger?"

In response I simply heaved in a deep breath, my body swelling rapidly. The material of my sneakers bulged and strained before the stitching and glue gave out, feet swelling to roundness. Up above my hands grew plumper, and even my head gained a larger, rounder shape. More of my gut emerged from between my shirt and jeans, and when I stopped again I was double my old size.

I felt a hand touch my underside, drumming a finger against me. "This is so weird." They stepped into view, looking up at me. "So can you get bigger?"

"Yes." I breathed in for emphasis, rising another several feet. "It's pretty easy."

"Maybe you shouldn't, though." Her voice sounded nervous. "You're kind of sticking out."

"Am I?" There was a hollowness as I took in more air, the band of skin across my midsection growing wider, my navel deep-set as I watched tops of trees and windows grow closer. The rest of me grew, but not as fast, leaving me increasingly misproportioned. As if I had any sort of proportions now short of-

"Stop, please! You're too big!"

Her words gave me pause. Here I was, looking out at my body stretching off and downward, taking up most of the area between the apartment buildings, heads level with their roofs... and this was "too big."

It was the single funniest thing I had heard in ages.

"Too big?" My entire body shook as I laughed. "Too big! Let me show you how big I can really get!" With that I huffed and puffed, shooting up and out. I felt the apartments press into what were my hips, then my thighs, then simply give way as I grew. I watched as the stories of skyscrapers shot by, buildings being pushed over by body as dozens of yards were added to my waistline in seconds. My head grew level with the tallest buildings, then grew beyond them as I became the highest point around.

"I'll be bigger than this city!" The devastation caused by my growth was little more than shifting stones against my underside. As my head broke the cloud line I began sucking them in with each breath, clearing the skies around me before I shot past them. The hanging moisture flowed to where my shoulders were, then my waist, left behind just as surely as the man-made structures I was overshadowing.

"Bigger than this state!" My head was huge, my cheeks were blimps unto themselves, and yet all around me was a field of stretched fabric, the horizon growing more distant by the second. The blue of the sky faded to black as I breached the atmosphere. Down below the city had become too small to be relevant as entire counties were thrown into darkness.

"Bigger than the country!" At last I felt myself lift away from the ground, lazily floating upward. A deep huff caused me to swell several miles, backside hitting the surface of the planet with a quiet, distant crunching sound as the force propelled me up and away. The lack of pressure in space was freeing as I tumbled and turned, and I could feel my body creak and throb as it grew at an unimaginable rate, watching as as my shadow across the continents grew larger. I was a second moon, far closer, and soon far bigger. Everything was stretching and filling beyond any comprehensible capacity, and as the darkness engulfed the entire planet, only then did I stop.

My hands and feet were puffy and bulbous, easily able to flatten entire mountain ranges. My head was blimped up enough that I could simply float towards the surface, put my lips to the ocean, and suck it all up and hold it in my cheeks. But everything... a single person, now thousands of miles across, full of vast amounts of gases. Through the haze of the planet's atmosphere millions upon millions of people would look up and see me floating nearby. A human balloon bigger than the Earth, and yet still growing larger, as thanks to the warmth of the sun heating my contents I could feel myself gradually expanding.

But then a thought came to me.

What do you even do for an encore?