I'd condense it further:
Tamers12345 is a YouTube animator that used to make bad on purpose fan cartoons of the 90s cartoon show Sonic Underground that were unironically really funny.
It had classic Newgrounds and South Park style edgy humor that made fun of the types of fan cartoons people would make. Tamers would deliberately add poorly drawn "fan service" where characters will have giant spherical poopy asses, mocking how Internet degenerates will make gross porn of children's characters. It also had unironically well crafted jokes, turning the 90s adventure cartoon into an It's Always Sunny in Philadelphia style slice of life sitcom where all the main characters are irredeemable assholes to each other.
Unfortunately, Tamers's fanbase started becoming too unironically invested in the characters and Tamers became the thing he mocked, adding actual well drawn fanservice for people to masturbate to into his videos. My personal belief is that Tamers started working with a small team of writers and animators that convinced him to move in this direction as a way to earn more Patreon money (you can see scenes where the art visibly improves in the later episodes).
This culminated in Tamers moving away from Sonic Underground entirely to focus on making cartoons based on My Little Pony and, recently, something called Dandy's World. This has landed him in hot water, as Dandy's World is something enjoyed mostly by little kids, and Tamers's videos are at this point basically just violence and porn of characters that look like babies.
TL;DR: funny internet parody animator eventually started making softcore porn targeted towards kids.
