https://www.reddit.com/r/Adblock/comments/70xaqa/a_they_live_adblocker_details_in_comments/

This uses Catblock with a custom image set, but Catblock hasn't been updated in 6 years, so I don't know how well it still works. Anyway, if Catblock won't work, we have to find a blocker that allows for some customization and then fit those "They Live" images in.

(I'm trying to get Catblock to work, but somehow I can't find any pages that even load ads? I think the pihole is blocking the scripts that would load the ads.)