* AnticlimaxBoss: Compared to the hell you had to go through to get to him, [[spoiler:Andor Drakon]] isn't particularly challenging.
* BreatherBoss: Yulgash, the Master Summoner. He comes a few floors after the battle bunny level and the cat lord, but his temple isn't particularly tough, and Yulgash himself is a SquishyWizard. Most players just dash in and hack him apart before he gets a chance to fill the level with monsters.
* DemonicSpiders: Including literal spiders, who get summoned in hordes and have poison attacks; jackalweres, who summon legions of increasingly-powerful jackals, the greater claw bugs and killer bugs in the Bug Temple, and pretty much everything you meet in the Final Dungeon.
** Ghosts can pass through walls and have an aging touch, making them this to any player race with a short lifespan. A "tension room" full of ghosts can easily surround an orc or troll in a corridor and age him to death.
** Ogre magi are at ''least'' as tough and strong as normal ogres, [[HealingFactor regenerate their wounds]], ''and'' can cast invisibility on themselves and ice spells at the player.
** Dark elven priestesses, princesses and wizards (called [[FanNickname spider factories]]) are particularly nasty summoners. Not only they summon hordes of spiders, which fill the area with immobilising webs and use poison, but have themselves nasty attacks such as paralyzation and energy ray spells.
* GoddamnBats: Summoners of any kind can quickly become unbearable. Karmic creatures are just as bad, because hitting them causes your character to get cursed and/or doomed, which is a highly undesirable [[StandardStatusEffect status effect]]. And also [[spoiler: cats. Killing even one of them makes an enemy of a high-level NPC in the end game instead of a very valuable artifact ring.]]
* GoodBadBug: Let a dragon pick up a pile of gold. Kill the dragon. Notice that it gives you twice as much, every time. Lots of fun with vaults, although you've got to be careful if the dragons have a breath weapon that can melt/dissolve the gold.
** If you are a Monk and have a nonhostile creature standing next to you, typing "n" to the "are you sure?" message when you use your circular kick results in the kick going off anyway. Bad, right? Not when you notice that it takes '''zero''' turns to execute and only hits hostiles.
* ThatOneBoss: Several.
** The Ancient Chaos Wyrm is the boss of the Tower of Eternal Flames. Not only do you have the Tower's environment to deal with (see below), but the wyrm is an exceptionally powerful opponent. It can breathe fire (although you should be ready for that) and powerful energy rays, as well as attacking with confusion and powerful melee attacks. Furthermore, it's very tough, fast, and can heal itself if you manage to wear it down. Just for more fun, the temple is also full of tough fire elementals, demons, and grues.
** Nuurag-Vaarn, the Chaos Archmage. For starters, he's located in the Mana Temple, at the bottom of the Unreal Caves, which are themselves at the bottom of the Caverns of Chaos and have a massive corruption rate. Just getting to him requires you to go through a massively trapped hallway, all while magebane and magedoom eyes are draining your PP. The Archmage himself attacks with powerful ice and shock bolts, death rays, can drain stats in melee range, and frequently casts darkness and invisibility spells.
** Keriax, who you must kill for any advanced ending. Keriax is the Ancient Chaos Wyrm on steroids. He can breathe bolts of all four elements, as well as bolts of corruption, all of which are immensely powerful. In melee range, he has five attacks per turn that poison and drain stats with frightful efficiency. He can also confuse you ''and'' has massive HP regeneration. If you can't figure out his WeaksauceWeakness, good luck. [[note]]Thrown potions of cure poison will incapacitate him for several turns[[/note]]
** The cat lord. He is tremendously fast and nigh-impossible to escape from, often outrunning players with high speed or seven league boots. He attacks multiple times per turn, has a high to-hit, and always punches through armor. Thankfully, he's a SkippableBoss, but reaching his level without making him hostile is easier said than done.
* ThatOneLevel: The Tower of Eternal Flames is infamous among the fandom for being a 'make or break' point for most characters. For starters, it deals constant, massive fire damage to both the player and his/her inventory. Protecting yourself requires multiple counts of fire resistance, some of which have to be gained intrinsically. Protecting your inventory is harder; a blessed fireproof blanket will protect your inventory, but not what you're wearing. A blessed ring of ice will cover them both, but it's not 100% guaranteed to work. This is all before we get into the matter of the monsters within, or the chaos dragon waiting in a room full of demons at the top.
* ThatOneSidequest: Most of them. Even trying to save the little girl's puppy has a time limit and puts the PC through a dungeon with a guaranteed giant ant hill on the second level. Giant ants have sturdy natural armor and they are ''mean.'' (Additional fun awaits closer to the bottom of the dungeon.)