The random death of a cat might be the most shocking moment I can remember in a game.
I'm playing Divinity: Original Sin 2 [official site], and it's my first experience of the series as a whole. Not knowing what to expect, but knowing the game to offer unexpected moments, I was simply pootling around the island on which magic-laden beings were being held captive. And at a certain point a black cat started following us about. A very welcome black cat, causing no trouble, a little too meowy but nothing offensive beyond that. It seemed to have an odd look in its eyes, and I was intrigued to learn if there might be more to this mog than met the eye.
After a bit I got used to it, almost as if it were a member of our party. It'd figure out its own routes if we climbed somewhere it couldn't, it kept itself busy while we were engaged in fights, and generally mooched about in a very harmless fashion. My son named it, with the imagination of a two year old, "Meow", and so it was. Meow the cat.
Then chatting to some grumpy Magisters outside a locked gate, mid-conversation with one of the soldiers, I heard first the sound of an arrow being loosed, then a gruesome squalling feline gurgle, and there on the ground beside me was the bleeding remains of Meow. Dead. The bastard on top of a lookout tower just took it upon himself to kill my pet! My innocent Meow, who had been nonchalantly sniffing about, not even disturbing their hound.
My jaw hung slack, and then stayed there. I processed what had happened. This NPC had murdered an NPC kitten. I was chatting! There was no warning! And there was nothing I could do - not only was I mid conversation with the bastard murderer's colleague, but these were all level 4, and I've just started, I'm level 1, and I wouldn't stand a chance in seeking brutal justice for my little kitty's life. And my jaw was still hung open.
It was a moment just so brutally shocking, despite being I of course realise, completely irrelevant to the game at large. The cat wasn't my pet, it was just following me about. I couldn't interact with it in any meaningful way. It wasn't a "pet" in the sense that RPGs understand. A stray cat was killed by a guard. A bastard guard. But the randomness, the helplessness of it, struck me incredibly hard.
Games don't do that! Games, as they go, tend to be so clumsily choreographed and signalled in their Moments, usually resorting to cutscenes for occasions when they want to emotionally shock you. There's so little that's random, so few moments in the whole genre (and, let's be fair, in film, TV, too) where something completely unexpected happens, and no one at all gives a shit.
As it happens I clicked on the gate to see what would happen, causing all the guards and their mutt to launch at me, inevitably seeing my party of two weaklings die. So I've reloaded to the moment before the kitty demise, and now I'm absolutely transfixed with fear that little ol' Meow could be met with cruel death at any moment. I can't think of a time a game's stakes felt so high.
(Postscript: I went back to the moment to see if it would happen again, and indeed it did, this time with the characters commenting on the events. The (bastard) guard justified his brutality by saying, "Bad luck to let on 'a them cross your path." Weep.)