I made this just because I can. The characters I have chosen & gave them a slight story in my own head-canon.

1- Bloated, Harahara from Future Card Buddyfight Ace
Harahara eats a lot of food & Agito decides to try to help him lose weight. One of the ways to do it is to use an air pump & Harahara inflates like a balloon.

2- Garbird from Future Card Buddyfight Ace
Garga hears an old story/rumor of Garbird being a giant & asks him, but the story was that he became a giant balloon.

3- Batzz from Future Card Buddyfight X
Batzz one morning was watching a cartoon & a character in the cartoon thumb-puffs to giant-size. Batzz decides to try it out, but he accidentally becomes a blimp.

4- Humungousaur from Ben 10
Humungousaur was looking around Undertown & he spots a vendor handing out samples of a Power-Up Juice. Humungousaur tries one & he was told to take a deep breath. He does & he grows twice his own size & does it again & again until he becomes a giant parade balloon. (  luigi9004 helped me with this story.)

5- Veldora from That Time I Got Reincarnated As A Slime
Veldora while inside Rimuru want to see how long he can hold his breath for. He takes a very deep breath, but he took a breath so deep that he inflated his own belly & he's worried on what would happen if he releases it.

6- Vector the Crocodile from Sonic
Most of you know about the time he became a giant for a comic. Before he became a giant, he inflated like a balloon & he had become a huge balloon.

7- Gabiru from That Time I Got Reincarnated As A Slime
Gabiru has a pretty big ego but Rimuru wants to try out a new ability called "Liquid to Air Conversion" & use it on Gabiru. He tells the Dragonewt to drink a lot of water & after a while, his belly was big & full of water. Rimuru uses his ability on Gabiru & the Dragonewt's belly expands rapidly quick.

8- Grimlock from Transformers
Ratchet was fixing Grimlock after a battle & after his fix-up, he spots a can of what he thought was oil. But it was actually an experimental Bubble Float Soda. Grimlock drinks the whole thing & eats the can. He belches out bubbles & feels funny on the inside. Grimlock notices that he's starting to grow, but he suddenly realizes that he's actually inflating & fills up the entire base. The Decepticons STILL haven't found the base. Somehow...

9- Tannin from High School DxD
Tannin was looking around some old castle ruins & he spots an old jewel. He picks it & the jewel glows bright & it turns to dust. Tannin was confused & disappointed about the jewel's disintegration. He feels his muscles inflating & shortly, his whole body inflates like a balloon. Tannin decides to stay at the ruins until the effect goes away.

10- Drago from Bakugan Battle Planet
Drago had caught a cold & he holds his mouth shut to stop sneezing. Gorthion tells Drago that he's gonna blow up. Nillious was watching close by enjoying the show. Drago was about to sneeze until his sneeze blows back into his body & inflates him to almost the size of a human size ball. Gorthion & Nillious just stood there looking at the big round Dragonoid.

I hope you enjoy my first posted Inflation Meme. Look forward to a Part 2 with more characters.