The story of the man and his chicken did that for me ... : http://www.mangago.zone/read-manga/children_can_t_choose_their_parents/ - just too weird.
they're both weird af
This one did that to me, here's a summary: there's twins where one killed the other and after fell in love with an author who connected spiritually with the dead twin and had mental sex with the dead one behind the alive twins back. Somehow he brought the dead twin and alive twin together mentally to have sex since the dead one had been in love/obsessed with his twin and the author just wanted them together. In the end the twins end up together and the author dug up the dead twins grave and the alive twin licks his bones to connect...They all end up together in some disturbing way...
http://www.mangago.zone/read-manga/samenai_yume/
Okay, we've seen the chicken-yeti-dead guys, but bonsai?
http://www.mangago.zone/read-manga/nightmare_fortress/
... admittedly, Uki Ogasawara draws the hottest pine trees ever ...
There was also the one where the guy took a bite into a mochi and it turned out to be a deity's butt, which he then proceeded to rape mochi the deity. http://www.mangago.zone/read-manga/kunpuu_tango/
Djidod
Have you ever read a yaoi that was just so weird that you just say "That's enough internet for today"? For me, it was the one with the chinko. Not that the story was bad (I actually find it to be one of my favorite), but it was just plain weird.