I'm starting up a 5e DnD game with some friends over Roll20. We've done a few games, trading off the role of DM every two months or so and my turn's comin' up. So, what I want to ask you /tg/, is what are some of your best "Mind-Fucks" you've given your players?

To give a little bit of info, my campaign will consist of the party being lured to an island who's having trouble, standard fare with monsters and the promise of reward, meet other mercenaries there who answered the call as well, etc. etc. However, on their way there, they are "forced to stay" and find the island to be quite ... fucked up.

The island itself is a mashup of almost any and every trope I could find in horror, Lovecraftian myth, and nightmare inducing monster I could find. What I really want to do however, is mess with their heads. We use Roll20 and Skype and the DM whispering players is common place in our group for subtle player actions only certain people notice, so I've already got tricks such as telling Player A that Player B stole from him or was mentioning something about doing the mission "their way" - stuff that would cause them to become paranoid or selfish as the become more unstable (Taken a few notes from Darkest Dungeon as well).

So yeah, as a general topic, what tricks do you fellow DMs play on your players to really screw with their heads or perhaps just simple horror/suspense tactics you like to use?

Attached: their first encounter