When you were younger, all the kids would hop on any rumor of a legendary being near, the overzealous kids even brought Pokeballs to try and catch one. Nobody ever did and most rumors were fake, but you never gave up! You heard rumors of a Ultrabeast portal opening up at the top of Hulu Mountain, you went to investigate. You hear loud rumbling in the trees, and you see it... a Guzzlord woman!

Go Pidgey!

....

Oh no, in one attack your Pidgey(your only pokemon) was downed... Return Pidge-

Before you could even call back your Pokemon, the Guzzlord had grabbed it, and shoved it into it's mouth. It swallows the Pidgey down, sinking down into her gut... time to run.

You try to rush to safety, but the giant Guzzlord woman is far to large and fast, quickly grabbing you. It lifts you closer to it's open maw... You curl into a ball in fear, it gets the Guzzlord woman's attention she grins before putting you down. You lie on the floor for a bit before getting up, confused. You back away slowly from the Guzzlord, and it follows you every step. You turn and run, the Guzzlord's giant footsteps close behind. Soon you get tired and just start walking home, Guzzlord keeping pace right behind you.

It frequently grabs and swallows other random Pokemon, alive. They all struggle in her belly as she rubs it, burping along the way. They digest quickly, adding to the fat body of the Guzzlord, usually making her boobs and belly bigger.

Soon you arrive home,

Mom: "Did you catch the legen-", you're mom is in shock as the Guzzlord tries squeezing her fat body through the front door behind you. "What the heck is that thing?!"

She pulls out her pokedex and scans the Guzzlord, it reads: "A Guzzlord, the stomach pokemon, an Ultrabeast that is a constant state of hunger, very dangerous, call police if spotted"

Mom: "We gotta call Officer Jenny!"

You sigh, "I already did, she uh..."

The Guzzlord woman burps, and out of her mouth comes a partially digested officer hat.

Mom: "Oh... did you try catching it with a Pokeball?"

You: "I did... it doesn't work."

Mom: "Oh well uh.... Congratulations on your new Pokemon I guess..."

You stand there and ponder... I guess this a powerful Pokemon, and it seems to follow you... You wonder how your journey to be champion will be now!