Nehrim/YMMV


 * Demonic Spiders: Those damn acolytes if you're a mage. With their reflect magic, and spell absorption, you often end up killing yourself with your own magic while they smack you around with their claymores.
 * Also the actual Tarantulas. They're all over (one right outside the start of Part One!) - they're tough, spam paralytic spells so you spend more time on your face than your feet, and on top of it you don't even get to harvest any venom from them.
 * Game Breaker: The Magic Winds armour sets if you're a mage, with its massive magic regen bonus spamming high level magic attacks and backpedaling away from enemies makes the game pathetically easy.
 * Nightmare Fuel: Several.
 * The giant spiders are moderately terrifying in large numbers.
 * The old kingdom of the Dwarves. In fact, one part
 * When running away from the guards in the Southrealm Temple, you enter a cave. Inside the cave you come across this massive thing laying spider eggs. As you progress, suddenly there's a loud crashing sound and you realize that the thing is following you. You seem to escape it for a moment...Then it eats you. You survive. And no other reference is made to it.
 * That One Quest: The Professional. Oh god, The Professional.