Interestingly, before I'd read past the first paragraph I was already google'ing "Kuiper Belt object IDK86113" before reading on, so that I'd have some context for the rest of the post.... I wasn't finding anything until I added quotes and saw this was the only result.. then read the rest to see it was fake.

Upvoting posts like this is how headlines become news, so I can't participate in that.

Anyway, during my research I learnt that there is a working theory by various scientists that there is another large planet orbiting beyond Pluto. Here's a link to the NASA page and here's a video from Caltech: