According to few assumed theories in Internet culture, the way we see it today, Shitposting over the Facebook was introduced and injected among the Facebook users by a guy called Shiit Kiid a.k.a. Shïït Kïïd. The first ever actual trendy Shitpost on Facebook was made by Shiit Kiid. Around 2015, on Facebook, he actually started eyecatching trendy Shitposting that used to end with the line "SHÏÏT POST FROM SHÏÏT KÏÏD" and immediately his followers started responding to make it viral that even the Trump's people caught the eyes to use it in his campaign.
"According to his recent updates from August, 2022 Shïït Kïïd is now planning to introduce new and more improved version of Shitposting under a new name 'Shiiz Posting' which will be just focused on posting of Videos (where the post-creator self should be in the video) rather than Texts and Images and a new video genre called 'Shiit Video' with it which are expected to go viral too by 2023".
Here, is a video that Shiit Kiid posted recently which clearly defines Shiiz Post as a mix of Schizo Post and his new genre to the videos called Shiit Video which is kinda fun
Since 2013, his bit hideous but continuous presence as Shiit Kiid over the internet through Facebook, Instagram, Twitter, Snapchat, Youtube and Twitch where he clearly identifies himself as Super Hero who knows a lot about the Universe conveys that he is fictional, comical and creative content poster. Although, it’s still not clear that what country Shïït Kïïd belongs to but most of his followers believes that he belongs to the United States.
For more info about Shiiz Posting, Shitposting, Shiit Video and Shiit Kiid look on Urbandictionary and Wikipedia.