Lately I've been seeing a lot of pics with the same set up, a character is stuck in a hole/pit half way with the top half clothed and the bottom half being fucked by tentacles/roots/etc. I even swear I saw it on here. Just curious what spawned this trend.

Do you mean those memes where half a character's body is stuck in a whole and they're saying stuff like "Step-bro, please help!"?

Examples?: danbooru.donmai.us/posts?tags=through_wall+&z=5