the breather enemy, which is represented with an "o" in the ASCII tileset, is surrounded by multiple copies of itself, which could potentially trigger trypophobia.
Characters with the "Nyctophobia" trait panic in the dark. There are human mobs that run around screaming and panicking before they are killed by zombies.
There is a mob type in the game referred to as a "gawky guardian" which does nothing except run around and call out for their child, which always results in them being surrounded by zombies.
there a profession which allows you to play as a gimp, and you can stumble upon BDSM items such as bondage masks, whips, and gimp suits in certain locations such as houses or campsites.