I was digging thru my Google Drive recently, and came upon a 5e conversion of the octopin. I had done this write up in preparation of running Hall of Harsh Reflections, as part of the Age of Worms adventure path. HoHR is found in Dungeon Magazine #127. I only ran half of the adventure before starting a new campaign set in my world of Eska. Since I never ran the session, I never posted this conversion before. So here it is now!
Edit: 11/8/20. Changed the CR to 3.