The small purple legs flailed again after a long rumbling tone echoed through the woods. Only the legs weren't trapped under the big orange rump that sat on the poor Rattata's body. 
He could only stare in horror as the Arcanine slammed his ass on the little rat. The first four or five farts weren't that bad,  sure they stinked but they were bearable. The next five ones were hardly bearable but the last two ones were an other cup of tea. 
The grass around them withered immediately after the last one,  changing it's color nearly black.  
Rattata had to endure it too,  wishing to black out so that he hasn't got to smell it.  Unfortunately his body could endure much so that he had to take all of the farts. 
Arcanine moved his ass from side to side to rub his musk into the rat's fur,  adding more weight onto the small body too.  He knew perfectly how bad the situation was for Rattata but he didn't waste even one thought about mercy or something like that.  It was shown perfectly when the dog started to rip another bombastic fart.
Arcanine relaxed and let his gas freely blowing onto his victim.  What started as a silent hissing fart became a loud bassy gas bomb.  
Finally the rat blacked out after the 10 seconds long and very sulfuric fart.  The dog ripped another small poot before he stood up,  really proud of his work. 
Arcanine looked at the limb body and walked away "Next time I am not going that easy to you,  hehe "

Rattata wasn't by far the first victim of the mean dog. 
Arcanine lived in the Ilex Forest for about a month. Well, actually 'Arcanine' was there for two weeks.  
A trainer gave two Pokemon into the pension of Goldenrod City.  The result was an egg that contained a very huge Growlithe,  one and a half of the size that a normal Growlithe normally has. 
The trainer was very exited and wanted to train the Growlithe.  It seemed to work perfect since he was incredibly strong  but there was a big problem.  Growlithe wasn't only bigger than a normal one but also much gassier. 
The trainer could endure the smell and found it even funny from time to time but the older Growlithe became the bigger was the amount of gas. 
Battling wasn't possible anymore,  every time he had to give his opponent the finishing attack he had to fart.  The trainer had enough and freed him in the near forest. 
Since Growlithes usually don't life there he hadn't any fiends and could easily life there.  After two weeks there he saw a trainer loosing something that came out to be a fire stone.
He picked it up and wanted to give it back, instead he started to evolve and to become an Arcanine.
It was a very new situation for him but after one or two days he loved it.  He was still extreme huge and gassy but he had perfect control about his farts.  Cause of the amount he still produced he could pass gas whenever he wanted but he could also hold them back.  This ment that he could also use his strong attacks without stinky surprises. 
Three days after his evolution he got very cocky.  He started to force the Pokemon that were living in the forest to give him their food. 
Arcanine realized that it worked only a short time to  beat them up for disobedience,  he had to think about something new.  He knew about three special things about him: size,  strength and gassines.
Size already worked a few times. He could threat the others so that they won't fight but it resulted in the others hiding from him.  It didn't worked anymore. 
Strength was another option,  he attacked everyone who didn't what he wanted them to do.  It was very effective but shortly the others started hiding again.  Some started to get used to it and let him do it. The number of Pokemon who actually gave him food was way too small. 
He finally came up with a strange but extremely effective idea.  His very first victim was a Pidgeot and he loved to think back to it.  The poor thing was standing on a rock,  not realizing the big dog in front of it. He just had to sit down and rip his bombs. 
The others tried again to hide but all the dog had to do was farting.  There wasn't any place his farts couldn't reach.  Also everyone who smelled them didn't want to go through this again and those who didn't had to didn't want to try it. 
Arcanine got cockier and cockier,  the others feared him and did everything he wanted. Whenever someone thought about disobedience got farted on.  He forced them to do the orders completely perfect, even the slightest error was punished with farts. Of course he was doing his best to find any reasons for it. 
Arcanine didn't knew that a special someone was watching it... 

The dog was walking around again,  searching for a new victim. Filling Rattata's lungs with his toxic farts was a good warm up but he wasn't completely satisfied. 
Arcanine also felt how his bladder slowly reached his limits. "Well,  that gives me a good idea. Just have to find a good victim. " He looked around and started to grin widely when he found a perfect victim.
He headed straight to the Pokemon and spoke in his deep voice "Hello little plantlet... "
It was a little Oddish that was absorbing a bit of sunlight, fully relaxed. The more it was scared when it heard that voice.  The plant Pokemon didn't even had to turn to know who it was,  big fear shooting through his body.  "H-h-hello... " "Turn around and look at me! "
Oddish did as told and looked up into Arcanines face,  completely threatened. The big grin didn't help much.  "Well,  what do we have here...."
Silence 
"I'll make it short and directly, I gotta piss and this little bush here will make a great spot..." Arcanine was playing around with the leafs that grew out of Oddish's head. 
"Y-you a-a-aren't telling me that you want to p-pee on my head...?!"
Arcanines voice became loud and angry "Do you have any problems with that?! "
"N-no,  o-of course not... " The poor thing is lowering his head "Arcanine piss is very healthy, especially from such majestic ones like you... "
The dog was speaking normal and grinned again "Didn't expect something else " with that he is raising his leg. Oddish got into position and whined when he felt the hot stream pushing against his head. Arcanine just closed his eyes and relaxed as he emptied his bladder onto the poor little Pokemon. It was a powerful stream of very intensive urin. The hot and dark gold liquid slowly watered every tiny bit of the leafs that slowly started to hang down. The stream lasted two minutes before it finally stopped. 
Oddish wasted no time to shake his body dry,  trying to get rid of the pungent piss.  He stopped immediately after hearing Arcanines voice again. 
"Tse tse tse,  did I ever said something about cleaning it? "
Oddish's eyes grew wide "I d-d-didn't wanted to... uhm..."
The small plant knew that it was hopeless, he did something that gave the mean dog a good reason for a punishment and everything he could do would've made it worse. 
"Well,  you should be glad... " The dog walked in front of Oddish.  He tried to run but Arcanine just slammed his ass onto the ground,  squashing the poor thing under it. 
"...It's the first time that I am farting on someone of your kind "
Not even a second after saying this, Arcanine ripped a long SBD that deserved it's name. There was only an almost inaudible hiss that signaled the coming horror. It became extremely hot under the heavy rump and the little bit of air was changed with a very pungent stench. 
All screams and shouts were muffled. The only response that the little plant received was a very long and bassy fart that pumped a very sulfuric stench into Oddish's lungs. 
Arcanine slowly stood up and looked down at his victim who's leafs were completely withered.  "Hmpf,  be happy that it was the first time.  Otherwise I would gas you much longer. "
He spit on the unconscious Pokemon and left. 

Arcanine was walking around again,  searching for another victim. Suddenly he heard a slightly high pitched voice. 
"I can't continue to see you torturing innocent souls. I will put an end to this! "
Arcanine looked around,  raising an eyebrow "And you might be?  Your voice doesn't make me shiver,  that's for sure! "
Suddenly a small green Pokemon appeared in front of the dog "Do you even know who you are talking to? "
"I only see an annoying little thing that better gets out of my way! "
"H-how could you?! I'm Celebi and I'm the keeper of this forrest. I'll make sure that you... "
Celebi was interrupted by a loud yawn "Stop it,  you're too boring. Keeper or not,  for me you are only annoying. "
"Y-you! I'll stop you from... "
"Uhm, I think you are repeating yourself. " interrupted Arcanine "You told me about stopping me multiple times now but I don't see any results. "
"That's it! Prepare for your punishment! "
With that Celebi started to use it's Psychic attack.... at least it tried it.  Arcanine was surrounded by the typical blue aura but that's the only thing that worked.  Celebi tried to heave the dog with its psychic powers but he didn't move an inch. 
It was pretty logical, a much bigger size causes a much bigger weight too. Arcanine was simply too heavy for Celebi so that it finally gave up. Arcanine was very amused and started to laugh hardly. 
"Hehe, THIS is the power of the keeper? Now I know why the others here are so weak,  I mean if YOU are the keeper?! "
Celebi blushed,  it was embarrassed but even more angry "You will not be that happy when I am finished with you! "
"Awww,  c'mon.  What is someone like you going to do? "
The answer followed fastly when Celbie made a few quick moves with his hands.  It caused a bunch of plants to grow out of the ground,  creating a big cage around the dog. Giant thorns were supposed to prevent him from attacking the plants. 
"Well,  how about this? You won't come out of it that fast and even if you do,  I'll just create a new one "
Celebi was very proud and wanted to leave before it heard a strange sound. It reminded Celebi of a spluttering motor that it once heard when it visited the city. It worried the Pokemon when it realized that it came from the cage. It turned and stared in horror.  The thick wall of plants turned into a very dark color before they finally withered, revealing the widely grinning Arcanine. 
"Gotta admit that it was pretty funny.  But working?  Maybe with stones but plants just wither way too easy. "
Celebi was shocked "Y-you didn't just... "
"Farted me out of the plants?  Nah, pretty sure that you know that I did it.  Well,  I'm still pretty gassy... " Arcanine grinned even wider "...and since you had your turn even twice... "
Arcanine came closer and closer and Celebi was paralyzed by his fear.
"I think it's only fair if I have mine now! " 
The dog turned,  his ass facing the small Pokemon. 
"Y-you can't do this,  I'm the keeper of the forest,  I-I am a legendary Pokemon! "
Arcanine just walked backwards,  suddenly running with full speed.  Finally he pressed the Pokemon against a tree,  trapping it behind his ass. 
"Oh my,  I always wondered how it is to fart on a legendary one. I just wanted to rip a few ones onto you but now I have to enjoy it as much as possible... "
Arcanine opened the fart feast with a small squeaky poot that reeked extremely sulfuric. Already these two seconds were enough to make the green Pokemon scream loudly but it got muffled by the fluffy rump. 
"Mmmh, I love the sound of persons screaming under my ass "
The big Pokemon continued with a long SBD,  giving Celebi a good whiff of his pungent gas. The poor thing screamed and struggled widely but it didn't help,  Arcanine was just more motivated to torture his victim. 
The next fart followed,  this time an extremely long and vibrating one.  After that one he stopped for a while. 
Sure,  there wasn't new stink coming but the trapped gas was already enough for the poor Pokemon. 
Arcanine wasn't showing mercy, he had a simple but very mean idea that should proof his mercilessnes. Celebi still had to breath and the dog felt whenever it breathed in and out. He did nothing for two minutes just when his victim was going to breath in he ripped a very wet fart,  pumping his toxic fumes into the poor little lungs.  Celebi didn't even tried to do something against it.  The legendary Pokemon just breathed it in. It breathed out and in, another nasty fart. Arcanine kept it up for a few minutes.  Celebi wanted to die at this moment,  a dangerous amount of gas pumped into its lungs.
Arcanine started to rub his ass over the poor thing before he prepared the final blow.
"Now that you know your place you will be my personal slave.  You will do anything I want and everywhere I want.  I'll give you a final proof that I mean it! "
Arcanine pushed his ass as strong as possible against the tree. His belly started to gurgle very loudly and only a moment later Arcanine relaxed. 
The following fart went through almost all kinds of possible farts.
It started as an extremely low pitched one that made everything vibrating,  slowly turning into a very high pitched blast. 
It was a very deadly fart that smelled like spoiled meat, the heat making not only Celebi but also Arcanine's ass very sweaty.  The fart turned into a very disgusting,  wet one and finally ended in a hissing sound after 40 seconds. 
Already 12 were enough to knock the poor thing out coldly. 
Arcanine looked at his work and was very proud.
"Well,  I think my farts are legendary ones when they can beat legendary Pokemon... "
With that he left the keeper of the forest, green streams raising from it's body.