CQ - Sadhu quest monsters sometimes spawn inside solid blocks and immediately suffocate
I technically got this in a build from one of the private Discord channels, but after comparing the code, I'm fairly sure it isn't specific to that build.
Edit: I've confirmed using creative mode and editing the tags file that it also happens in 6.2.7. In superflat mode, the mobs spawned specially would be at most half-buried and not suffocate (except maybe the spiders), but with normal terrain gen just staying near a hillside is enough to trigger this, and I'm reasonably certain it could be further exploited by digging narrow trenches ahead of time.
Edited by MoonCutter2B