It's come to my attention that not very many people take advantage of the inflation gold mine that is Mammoth Mutt from the "Krypto the Superdog" cartoon. This is just a contribution to a field that shows much promise. Enjoy!

As of late, the Dog Star Patrol in charge of keeping the universe safe has been extremely busy. However, no dog felt the exhaustion quite like Krypto the Superdog. It wasn’t as if the Patrol couldn’t deal without him, but being the hero that he was, Krypto always placed himself in front of the line of duty, taking on the brunt of the jobs and leaving him terribly tired.
The Superdog enjoyed saving people, but even a hero as noble as him deserved a break once in a while. If anyone knew that, though, it was the inflatable pink Chihuahua, Mammoth Mutt.
She would often see Krypto putting on a brave face and telling the rest of the Dog Stars how ready he was for their next escapade, but she could see right through him. Every now and then she would spy Krypto sneaking as many minutes of sleep as he could before going back out to defend the world. Mammoth Mutt soon realized that it was taking its toll. She started to feel bad for Krypto. All she wanted was to give him a little relaxation. However, no one could convince the stubborn Kryptonian canine to take a breather every now and then, at least, not with words.
Luckily, Mammoth Mutt also noticed one other thing: the way Krypto would stare at her wide-eyed whenever she inflated herself like a balloon. She even noticed a little blush that would run across his cheeks when she bounced and rolled.
This gave her an idea.

As Krypto made his way to Mammoth Mutt’s room, he pondered the note that she had left for him in his room.

Dear Krypto,

I was hoping that you and I could meet in private to discuss battle tactics and enemy weaknesses so we can learn how to fight better. Do you think you can meet me in my room later tonight? I’ll be waiting.

Mammoth Mutt

Krypto rubbed his chin curiously.
“I wonder why she wants to meet in private,” he thought. “Something like this would be useful to share with the rest of the team.”
He shrugged off the thought. Krypto figured that the Chihuahua had a perfectly good reason for asking this of him.
As Krypto began approaching Mammoth Mutt’s door, he noticed that it was slightly ajar. He almost didn’t pay this any mind as he was about to enter. Suddenly, he glimpsed an image through the crack. He gave a curious whimper and peeked inside.
Suddenly, he found himself gazing at Mammoth Mutt, who had inflated herself into a ball. She shook her balloony butt in the mirror, admiring it. She rested on her bouncy belly and started rolling herself around, flapping her little paws as if she were helpless against her rounded figure.
Krypto couldn’t help but stare the whole time. He took notice of how hot he was feeling and his heart beating faster and faster. His head was reeling so much that he didn’t even notice Mammoth Mutt, back to her normal size, opening her door and looking up at the lovestruck canine.
“Is everything all right, Krypto?” Mammoth Mutt asked with a small giggle.
“Huh?” Krypto muttered.
He finally snapped back to reality and noticed Mammoth Mutt smiling at him. He began blushing and shaking his head.
“Uh, everything’s fine, Mammoth Mutt!”
“How long were you standing out here?”
“Oh! Uh…I j-just got here when you opened the door!”
She started giggling again, both dogs knowing perfectly well how false that was.
Krypto cleared his throat and said “You wanted to go over battle tactics, right?”
“Well, why don’t you come on in and then we’ll discuss what needs discussing.”
Krypto nervously entered the room as Mammoth Mutt closed the door behind him.
“So,” he began, “What did you want to talk about?”
“Well, for starters, why don’t we go over what you were doing just standing outside my door for so long?”
“Huh!? What are you talking about!? I told you I just got there when you opened the door!”
“Yes, but you seem to have forgotten that I’m a dog, Krypto. I could smell you the second you came up to my door.”
Krypto was a little embarrassed that he didn’t consider that.
“What’s more,” the Chihuahua continued, “I could very well hear your heartbeat outside my door. Why, anyone could hear it what with how loud it was.”
A blush ran across Krypto’s face and suddenly, he couldn’t think of any excuses.
“So do you want to tell me what you were doing out there?” she asked slyly.
“And do be honest.”
With a sigh, Krypto immediately resorted to the truth.
“I was staring at you showing off your inflated body…”
“And why would you be doing something like that?” Mammoth Mutt inquired.
“Because you look beautiful when you’re all big and round.”
Mammoth Mutt already had an inkling that he would answer with that, but hearing him say it made her heart go aflutter. She couldn’t help but blush and giggle at his words.
“You really think so?” she asked nervously.
Krypto was able to coax out a little smile—despite his nervousness— followed by a slow but earnest nod.
Mammoth Mutt sighed amorously and Krypto started giggling.
“Okay then,” she began. “Why don’t we forget about battle tactics and enemies then? I know the perfect way to spend this evening together.”
Mammoth Mutt approached Krypto and gave him a little lick of his muzzle. A shiver went across his white fur followed by a dizzy tittering.
With a large exhale, Mammoth Mutt began blowing up her body. She began filling out like a balloon, each of her features absorbing each other as her body became one continuous circle of air and bounciness. She made herself large enough so that she could still walk, despite her distended belly touching the ground. Why, with one good tip, she’d have to roll around to get moving. Compared to her gargantuan size, Krypto felt as small as a puppy.
Krypto watched entire thing with his tail wagging furiously. He was completely taken by her inflated figure. She batted her eyelashes at him lovingly.
“Like what you see, Superdog?” Mammoth Mutt asked enticingly, turning around to wiggle her bloated butt at Krypto.
“Like?” he asked. “I love it, Mammoth Mutt! You look so fun and bouncy and big! I can hardly take my eyes off you! You’re beautiful!”
“Well, the fun’s only getting started, Krypto!”
Mammoth Mutt tipped herself over onto her back, exposing her balloon-like belly to Krypto. He started panting loudly and tried to hold back a howl.
“Why don’t you break in this new bed, huh?”
Krypto was surprised at the question.
“You don’t mind? I mean, that seems a little forward for me.”
“I wouldn’t mind at all, Krypto! In fact, nothing would please me more than to have you snuggle on my big, bouncy, comfy belly. I’ll have you know that I’m quite warm, by the way!”
“In that case…!” Krypto began excitedly.
He flew high above Mammoth Mutt and fell right onto her belly. She started giggling at the tickle of being bounced on and the Superdog couldn’t help but to continue jumping on the giant Chihuahua like a trampoline. Her body jiggled with each successive bounce, making Mammoth Mutt giggle louder and louder with each landing.
After a while, Krypto finally settled onto Mammoth Mutt’s belly and pawed his way up to her head, touching her nose with his and licking her cheek.
“Thank you for inviting me to your room for this,” Krypto said with hearts in his eyes. “I’m having a wonderful time so far.”
“I knew you would. You look especially happy.”
“Is it that obvious?”
“Oh, yes! You know, you deserve a little fun and relaxation. You’ve been working yourself too hard lately.”
“But I’m a superhero! I can’t afford to rest when people are in danger!”
“I know what you mean, but if a superhero isn’t well rested, then he can’t save anybody, can he?”
“I guess you’re right, my big, bouncy darling.”
Mammoth Mutt giggled and being called that and Krypto covered his mouth in embarrassment.
“Sorry,” he exclaimed. “It slipped out.”
“I don’t mind one bit,” she said lovingly.
After a while of staring into each other’s eyes, Krypto began pawing and rubbing against Mammoth Mutt’s body.
“Do you know how lucky you are to have a body like this?” Krypto asked. “Being able to make yourself as big as you want seems so heavenly.”
“It is when you have someone to share the girth with.”
“Speaking of which,” Mammoth Mutt thought.
“Hey,” she began, “How about a kiss for your bouncy Chihuahua?”
“I thought you’d never ask!”
Krypto puckered up to give Mammoth Mutt a big kiss. She gladly accepted it and the two joined lips in passion.
Mammoth Mutt started to giggle and began releasing her air…right into Krypto’s mouth.
The Superdog gave a questioning muffle before he started feeling a strange sensation in his body, particularly his belly. He tried to release the kiss and turn to see what was happening, but Mammoth Mutt persisted with it, keeping Krypto enthralled by it. Even through his enthrallment, however, he finally realized in shock what was happening to him.
Krypto’s belly began inflating with air, giving off the illusion that he’d been putting on weight. His haunches and back fwoomphed outward and started filling out themselves, being absorbed by the weight of his growing tummy. He felt himself being lifted up by his new girth as he flailed all four of his legs helplessly in the air. His neck began being absorbed by the rest of his rapidly inflating body, fully rounding him out into a ball with useless legs. Even his cheeks were taking in some air, making him look as if he were holding his breath underwater. He was muffling in a small form of protest as his inflating belly lifted him high and higher. His expanding body felt strange, and yet…
Mammoth Mutt watched the entire scene in awe and amour. She very much enjoyed the sight of Krypto being blown up like a beach volleyball and not being able to do a thing about it.
Soon enough, Mammoth Mutt had returned to her normal size, having released all of her air into Krypto. She released the kiss and gazed upon her handiwork. Krypto the Superdog was now a helpless, inflated, volleyball of a canine, who was looking very confused.
“Wh-what did you do, Mammoth Mutt?” Krypto asked in panic.
“Isn’t it obvious? I blew you up like a balloon! Now you’re as big and bouncy as I was just a few minutes ago!”
Krypto struggled to get moving, flailing his legs and trying to roll himself around. All of his struggles, however, met no success. Even flying proved useless, as he awkwardly tried to lift himself up from the ground and found to his surprise that his balloony belly was keeping him down.
“Learning how to move around with a body like this takes time,” Mammoth Mutt commented as she rolled the inflated Superdog onto what used to be his haunches and climbed up to his face. “But you get used to it after a while!”
“Get used to it? You mean you’re not gonna deflate me? You’re gonna keep me like this!?”
“Uh-huh, for a while. Or as long as you like.”
“What?” Krypto yelped. “Why?”
“Remember what I told you about you needing to relax? Well, this is how you’re going to do it. If you’re all big and round like this, you wouldn’t be able to move as easily, much less fight crime.”
“Mammoth Mutt, how could you do such a thing? I have a duty to protect the universe!”
“I know how important it is, but like I said, you need a break! The Dog Stars will be just fine on our own, but once our fearless leader is well-rested, you’ll be back to saving the day in no time!”
Krypto mulled over her words for a bit and realized that she was right. He had been feeling exhausted as of late and rest would to him a lot of good.
“I guess I could take a week off or something. But don’t you think there are easier ways to get me to rest than making me into a bloated ball?”
“I guess there are,” she giggled. “But how many of them are as fun as this? You have to admit that you loved being filled with air and blown up like a balloon, didn’t you?”
Krypto realized that Mammoth Mutt was right about that too. He was huge, bloated, and probably looked like a round marshmallow. Yet, he felt nice and comfy in his helpless state.
“I…think you’re right. This feels wonderful! This big, bouncy feeling of my body is just irresistible!”
“I had a feeling you’d like it!”
Mammoth Mutt jumped off of the Superdog and rolled him onto his back, rocking him gently. He giggled at the sensation. She then jumped onto his bloated belly and started rubbing it.
“Who’s a nice big boy?” she asked playfully. “Who’s a nice big boy?”
Krypto started laughing uncontrollably at having his marshmallow belly tickled and rubbed.
“Me! Ha, ha, ha! I’m a nice big boy!”
“You know, I could teach you how to use this body if you wanted.”
“Really?” Krypto asked in astonishment.
“Oh, sure! I can show you how to roll and move around, even crush bad guys with your big self. I could even teach you how to inflate and deflate yourself!”
“No way!”
“Yes way! I could show you how to blow up only parts of your body. Like this.”
Mammoth Mutt took a deep breath and inflated only her stomach. She stood up on her hind legs, showing off her “plump” rounded belly. Krypto adored the sight of her, which was made clear by the hearts in his eyes and loud panting.
“You’d really do all this for me?” he asked dazily.
“Without question. Besides, even when I do deflate you, you wouldn’t like that, would you? I can already tell that you don’t wanna go back any time soon.”
Krypto blushed and smiled, giving Mammoth Mutt a cute nod of his head.
“It’s settled then! From now on, I’m gonna take good care of my supersized Superdog.”
“Sounds good to me, Mammoth Mutt!”
Mammoth Mutt rolled Krypto onto his belly and the two inflatable canines gave each other a passionate kiss.