Andrea went for a swim.
...In the entire Pacific Ocean, all at once.
It was the only body of water big enough to contain her now, as her growth had far surpassed anything sustainable for the planet in any way. Also, calling it a "swim" would be a bit of an exaggeration, since all she was able to do was splash around, wrecking the oceanic cities and countries all around her with world-record tsunamis as she played with her amazing size, making all the water on Earth completely undrinkable as her sweat and bodily dirt dissolved into the ocean, completely chemically altering the entire sea from north to south pole.
By now, the portal could function without her even having to move it, as by wearing it like a ring on her finger, Andrea could grow as much as she wanted, free from the size limitations of her former species' bodies.
Crawling out of the water, she dug her knees into China and plastered her hands all over central Asia. "How about we do something different...?" she said with a big grin as she crunched her hands into the crust of the Earth to give herself a strong grip. Shaking some water off of herself, Andrea's jiggling breasts slung water all across India and Tibet. Readying herself for a possibly jarring impact, she extended her arm joints as much as she could and sat down on her ass, flattening most of what remained of China.
"Preparing for impact, three...two...one!" playfully chanted Andrea, and after she reached one, she pulled her arms to her chest, jerking herself forward and down and slamming her breasts into the continent. Cracks spiraled out of control from the blast site as everything not made of sand in the entirety of western Asia and the Middle East turned to a fine powder from the pure brute force of her boobs' impact.
Within seconds she was on the other side of the continent. As she arrived in the ocean near Europe, she was once again welcomed by screaming from all the tiny, helpless people in the continent's cities and countries. "Maybe let's try a bit of a gentler approach." Andrea knelt downwards in the water, letting her tits fall downward as the grassy lands of Ireland and the vast British island welcomed her breasts' full, unmerciful weight in nearly an instant. Even with her gentlest boob-crushing, Andrea was still immensely destructive to the world around her, with northward sonic blasts obliterating the Netherlands, Belgium, and Luxemburg, as well as parts of Norway and northern France. "Guess I just can't help it, can I?" giggled Andrea, "I've simply rewritten the laws of nature, and now everything is just destruction, destruction, destruction..." She smirked down at France as she pounds it into nonexistence with her colossal foot, her sole sinking into the French terrain and forming new mountain ranges between her toes.
She recalled that morning, when she had dropped her phone and found her giantess fetish porn out in the open, and then remembered all of the tiny humans on Earth which shared her love of all things giantess. "You know," pondered Andrea, "I wonder if I have any fans down there...toppling world governments, stopping safety procedures, or maybe just masturbating their very hardest in my presence..." She dug her fingers through the African deserts, allowing herself to grow higher and taller with every passing second. "If any of that stuff actually ended up happening, just to prevent anyone from threatening my growth and rampage..." Giantess Andrea stood up, preparing her booty for another massive ass-crushing over all of the rest of Africa. "Well, thanks, I guess, thanks a lot." Andrea blew a kiss at the world, sitting down on Africa, her butt now dwarfing the entire continent for the first time. She made herself stop growing, peeling off her black bikini bottom and throwing off the top, briefly playing with her gargantuan, naked tits and running a finger across her nude, continentally humongous ass.
"You know, maybe I should leave a few of you alive as my worshippers... especially those of you who can give me tributes and art... I'd love to see what all of you tinies really think of me, once all of that silly fear is removed from your collective brains." Andrea balled her hand up into a massive fist and slammed it into eastern Europe, doubling down on all the destruction it had already received and ensuring no one survived there.
Andrea patted her shoulders as she squatted over the former subcontinent of Arabia. "It's going to be okay. You're too powerful to need to breathe, and if you do need to breathe, you can always keep this little planet around for it." Andrea nervously whispered to herself, preparing to fully stand up for the first time since her new size change. "Now..." Andrea chanted, "Three! Two! One!" Andrea rapidly stood up, thrusting her upper body above the atmosphere. Wondrously, she somehow didn't need to breathe, likely due to the portal's mysterious powers, although it did feel quite wierd being alive and painlessly existing without breathing, and it took quite a bit of getting used to before she was able to catch her balance on the planet below, her feet stumbling all over the former lands of Europe, Africa, and Asia as she balanced herself.
"Brrrr...it's cold up here, just as I thought." Andrea said, although no sound came out due to being in space, which was also very unusual for her to experience. Glancing down at the planet below her feet, she stuck the toes of her left foot into the gaping, molten hole she had left in most of North America's planetary surface, letting out an airless sigh of relief as she felt the gooey internal magma of planet Earth warm up her body from her enormous toes to her smooth face.
Smiling and confident once again, Andrea knelt back down into the planet's atmosphere. "Wow, that was an experience...thankfully I'll have forever to get accustomed to that starting later." She crawled on all fours all over her landing site, feeling the waters of the Atlantic Ocean slosh back and forth as she trudged along the shallow surface, the whole ocean feeling like barely a fraction of an inch to her. She crawled along Europe and into Russia, her hands and knees and feet crushing millions with every movement of her body. She caught a glimpse of Japan and sent herself flying towards it with a horizontal leap, landing on her belly and chest and creating even more monumental cracks all over the planet, completely decimating what little bit of eastern Asia she had not already destroyed...except for one country.
"Here you are..." Twisting the portal ring on her finger, Andrea made a ripple in the space around her, causing the islands of Japan to reappear out of nowhere, seemingly temporarily transported into another dimension or part of space for their own protection. Andrea held up the pebble-sized chunk of the planet containing all of Japan, just barely unscathed by her reckless actions. Andrea held up the country to her face; the citizens of Japan screamed as they saw her eyes hovering over their entire civilization. Andrea smiled smugly. "I like anime."
Tipping over Japan upside-down, she watched as all of its people fell out, except for a select minority she had selected due to their giantess fetishes. Andrea spoke to them. "Now you all need to promise that you'll make an anime movie out of me, like those Godzilla films, but like, way more sexy. Okay?" Andrea blew a kiss towards her Japanese hostage country. "...And don't you dare portray me as the bad guy!...Unless it's in a sexy way, of course!" She puckered her lips, re-disappearing the land of Japan to somewhere else in time-space again so she didn't have to keep up with it, but making sure that they had a good view of her rampage and destruction for...inspiration purposes.
Also because she knew how horny they'd all be watching her completely end everything she touched, and she figured they might as well get a good view of it all while it happened.
Andrea's tummy growled, snapping her back to her hunger. Getting back on her knees like a wild animal, Andrea bared her teeth and bit down on China, ripping it out of the Earth with her giantess strength. Chewing and crunching down on the country, she ran her tongue across it's lands, tasting a myriad of sweet and salty and spicy tastes all over her tongue before letting her teeth chew it all to bits. "Biggest country in the world?" Andrea mumbled with a full mouth, "More like biggest snack in the world!" She swallowed China, feeling the piece of planet make its way to her stomach.
Distracted by her antics of consuming China, Andrea accidentally sat on India, flattening the rest of it as her butt reshaped the Earth's crust around it into a perfect mold of her angelic cheeks. "I need to stop and grow now before there's nothing else to have fun with on this planet!"
Andrea did just as she said, shooting up in size, her butt covering more and more of Earth's surface as she burst out of the atmosphere, her feet and legs drooping over the side of the world, her ass spanning the entire Old World, nearly half of the planet completely gone underneath her butt. Her giantess ass became so big that the moon revolving around her pathetic little blue seat shifted it's orbit directly at her, rocketing strait towards her butt right before Andrea plucked it from space.
Andrea held the moon in her fingers, barely the size of a golf ball in comparison to her vast form. "And just where do you think you're going?" Andrea flipped the moon around in her fingers, placing it between her first and second fingers and grinding those fingers against it until it snapped, nearly disintigrating it except for a few tiny chunks of rock spewing off in all different directions. She put her powdery fingers in her mouth, nodding in pleasure at the bitter yet decent taste of the Earth's former moon. "Pretty good, but it's definitely missing something. It's a little bitter, but it's mostly okay...wish it had some life and liquid oceans for seasoning..." Andrea gazed down at the planet Earth below her, its dying, cracking shell being a surprisingly comfortable chair for her planetary ass to sit in.
"So..." boomed Goddess Andrea over the waves of space, her voice box finally having adjusted to the oxygenless expanse of space, "How about I taste this seasoned one?"