I'm always a little annoyed that there's a module called Tomb of Horrors, with a prominent and iconic annihilation thingy (they warn you about it in the 5e PHB, no less!)...
and then there's a module called Tomb of Annihilation, which as far as I can tell is much less about annihilation and much more about horrors.
How am I supposed to not mix those up?! From random bits and bobs I've heard I think they might even both have liches! Or maybe that's just me mixing them up!