goddamn motherloving mimics
I was running through Hell to kill the Wall of Flesh for a fourth time with a friend and on the way there, I noticed a locked Shadow Chest in front of us on the flat stone surface on which we were running. I went to unlock it, not realizing that such an out-of-place Shadow Chest couldn't possibly be real, and sure enough, mimic.
Also, is anybody else experience this glitch where parts of Bone Serpents or entire Bone Serpents will come up to much higher layers of the world, and only be visible to some people on the server? While my friend was on my server, he commented that he just saw a Bone Serpent come up through the ground, and we were on the surface. I've noticed the same thing as well, although I've only ever seen the heads of the Serpents float up through the ground before.