In a homebrew (the GM insisted that it was 3.5, but it clearly wasn't) campaign, the party (lv 3 by then) was escaping from some underground cult and traversing an ancient dungeon.
One of the PCs was playing a sand giant (yup!) with class levels from the Book of Nine Swords.
We arrive to a great underground chamber, and after a few steps we activated a trap so old that it was almost at plain sight. After a couple rolls in Knowledge (history) and Knowledge (engineering), the party wizard inform us that there might be several of this kind of traps around the entire chamber and they react to vibration.
My PC (a sneaky-type swashbucker) scout ahead and was able to see the chamber's guardian:
A Spectral Beholder (CR 18 IIRC).
As my PC warn the rest of the party about the Beholder, the giant proudly announce that the punch the floor to set off the nearby traps.
The entire chamber rumbles.
The party's wizard frantically tried to stop the giant from calling the Beholder. The giant's player said that he deliver three more strikes.
The wizard's player (my brother) literally stand up enraged, almost flipped the table and left the room for about half an hour.
I wonder, what were the names of the characters in your CoC game? I would really like to know.
We didn't. None of us knew any Serbian names for certain, so we had our characters using code names the entire time. Whenever someone needed an actual name for them and we couldn't safely reveal their employer, we had the characters make up American-like names and claim to be working for the U.S. Army. Given how famously neutral the U.S. was prior to World War 1 and how it was a nobody at the time, this worked rather well.