* DemonicSpiders: Loads and loads of them - in fact, a key part of ''Angband'' strategy is just ''not to get into fights'' with creatures like these.
** Hummerhorns (giant wasps) have a horrifying combination of two abilities; a bite that causes confusion, and the ability to ''self-replicate''. If you have just one of these on your hands and you don't deal with it immediately, you're in for a world of trouble - its confusing bite will hinder you from acting while it happily replicates around you, surrounds you, and bites you to death. Even a high level player can be taken down by these if they haven't taken precautions.
** Zephyr hounds come in huge packs and have various breath weapons, which they won't hesitate to blast you with.
** Quylthulgs are immobile piles of rotting flesh with various teleportation abilities.
** Drolems are the reason you ''never'' go below 2,000 feet without poison resistance. They're dragon golems with powerful poisonous bites and breath weapons - and being golems, they're immune to many things that biological dragons wouldn't be.
** Ancient Multi-Hued Dragons, etc.
** "It moves [[LightningBruiser very quickly]]"
* GameBreaker: Like in most roguelikes, being fast. The most dangerous monsters are those that can hit you 5 times each time you move.
* GoddamnedBats: Oozes, icky things, mushroom patches, and worst of all, worm masses.
** Zephyr Hounds. Almost any time you see a "Z" on the screen (the earliest ones--Clear, Dark, and Light--are the sole exceptions) you'll want to cry.
* GoddamnedBoss: Smeagol. Wormtongue to a lesser extent, as he is actually threatening.
** Any boss that summons. Especially when those summons can (and do) summon.