In many games, particularly older ones, there are mobs that prowl around that will end you quickly if you encounter them. Depending on the death mechanics of the game, that encounter may not be over with after just one death.
Personally I love this stuff. It makes the game scarier, and for me more immersive.
My favorite of all time was Equestrielle the Corrupted. It was a black, evil looking horse that lived in Lesser Faydark in EQ. You never knew when it would come at you out of nowhere and knock you stem winded.
Here you were, in an area where you are already nervous about getting killed by tiny, hard to see brownies, and you have to worry about this crazy house too.
Anyone like this type of encounter besides me?
EQ1, EQ2, SWG, SWTOR, GW, GW2 CoH, CoV, FFXI, WoW, CO, War,TSW and a slew of free trials and beta tests