Not every monster in Dungeons and Dragons has to be a high CR to be a challenge, as some creatures can provide an unexpected difficulty to a group of characters. Some monsters have abilities and attacks that defy their assigned level, having the skills to wipe out parties if they aren't prepared. Depending on the creativity of the Dungeon Master, some monsters will shock players with how dangerous they are.

The challenge of different monsters depends on what level parties are when they encounter them. Not all the deadliest monsters in Dungeons and Dragons are CR 15 and above, as many are proportional to how they exploit characters of various levels. For example, Intellect Devourers are easy to deal with in a Level 12 party, but a Level 3 or 4 party may struggle to take down that monster.

10 Stirges Can Swarm Any Party

Small Creatures With Deadly Attacks

Stirges are small, bat-size vermin creatures with mouths shaped like a dagger, using them like a mosquito to suck the blood from their prey. On their own, these monsters are easy to defeat, only possessing 5 Hit Points. However, when enough of these monsters swarm together, they can be a monstrous force that flies through the skies and latches onto unsuspecting prey.

For the new 2024 D&D Monster Manual, a Swarm of Stirges is a brand-new stat block that gives this creature more damage and health. This makes it easier for a DM to run a swarm of them as an encounter.

The single Proboscis attack from a Stirge causes it to latch onto a character, dealing initial piercing damage. While a Stirge is attached, it can inflict Necrotic damage at the start of each of its turns without having to roll to hit that same character again. This uninterrupted damage makes removing a Stirge crucial, leading to panicked moments for a party if there is a swarm of them all attaching themselves to different targets.

9 Froghemoths Devour Squishy Party

Goofy Monstrosity Players Shouldn't Underestimate

One of the more comedic monsters you'll find at CR 10 during a D&D adventure is the Froghemtoh, a massive Monstrosity that looks like a mutated frog. This giant abomination has three eyes, tentacles, and the ability to swim. Typically, this creature has a bonus to Stealth that allows it to hide underwater, ambushing prey that travels along the swamps or wetlands it inhabits.

What makes this creature so dangerous is not just the multiple attacks it makes, but the ability it has to easy grapple targets with those attacks. Froghemoths can follow-up tentacle attacks with a Bite that swallows players, forcing them to take Acid damage while ingested. With a Tongue attack that has a 20ft range as well, the Froghemoth can even pull creatures toward it to set up its Tentacles or Bite.

Even though Froghemoths possess a Shock Susceptibility to Lightning damage that inflicts debuffs, this isn't something most players will know about. The Huge size of a Froghemoth also makes it hard to deal with for characters who like grappling targets, especially since the creature also has a high HP pool that makes it difficult to take down.

8 Minds Crumble To The Psychic Gray Ooze

Don't Make Intelligence Your Dump Stat Just Yet

The Psychic Gray Ooze is a monster that represents one of the most terrifying Intelligence-based hunters since the Intellect Devourer. While this blob of corrosive slime moves slowly, it packs a punch with an acidic Pseudopod limb that deals above-average damage for a CR 1 creature. Furthermore, when this Ooze hits with this attack, it causes a target to have disadvantage on its next Intelligence saving throw.

The most common dump stat, or lowest stat, for a D&D character is often Intelligence. While Wizards or Artificers are built around having a high Int, most players will opt to have this score low, making creatures that attack Intelligence extremely potent.

The ultimate ability of this Ooze is its Psychic Crush, which it can use against any creature within 60ft of it, making its lack of speed irrelevant. When this ability starts, a creature the Oooze targets must make an Intelligence saving throw or take 3d6 Psychic damage. On top of this, the Ooze can inflict Psychic damage as a Reaction when it fails a saving throw, giving it two sources of a deadly damage type that can tear through low-level parties.

7 Quadrones Pick Opponents Off From A Distance

Attack Adventurers Like Clockwork

At first glance, the Quadrone doesn't seem like much, acting as one of the many construct Modrons in D&D players might find in the realm of Mechanus. Now called the Modron Quadrone in the 2024 Monster Manual, this CR 1 creature has a flying speed, but not too many Hit Points. What makes this construct deadly is their Gears Launcher attack, which can hit a target from an absurd 320ft range.

With the impossibly large range of its attack, the Quadrone becomes far worse when you realize it can attack four times in a single turn. Similar to the equally deadly Pentadrone or Tridrone, the Quadrone deals Force damage, which is rarely resisted by any party member. This creates a situation where multiple Quadrones can snipe players from afar with consistent Force damage, delivering a TPK fast against low-level groups.

6 No Secret Is Safe From A Nothic

Can't Hide From Creatures Who've Seen Everything

The Nothic is a CR 2 Abberation whose twisted bodies are defined by a haunting, glowing single eye that stares unblinkingly towards its foes. Nothics are former scholars who've been twisted into otherwordly shapes, twisted by forbidden knowledge they've discovered. As a result, there's no hiding from a Nothic, as the monster has 120ft of Truesight that will make any attempts to sneak past them with Invisibility useless.

Any Nothic can use an ability called Weird Insight as a Bonus Action to learn a secret about anyone it targets. Dungeon Masters can use this ability to have Nothics taunt party with their darkest secrets, or have the monster learn of their weaknesses for a combat advantage.

Nothics are horrifying guardians of secrets to come across, especially at lower levels. This is due to their Rotting Gaze, an attack that imposes a Wisdom Saving Throw. On a failure, any target within 120ft that a Nothic used this ability on must take an astounding 5d6 Necrotic damage. Characters with lower health might instantly be at risk from one Action of a Nothic, with groups of Nothics posing an even graver threat.

5 Kobolds Can Be Creative Threats In Packs

Small Inventors Pose Unorthodox Dangers

Any type of Kobold is seen as a joke in D&D, as these creatures are usually dumb, tiny lizards with very little health to pose any type of threat. However, a creative enough DM can put together a ton of little minds to create truly devious situations. As of 2024, Kobolds come in two types, including:

• Kobold Warrior - CR 1/8 creature with a Dagger
• Winged Kobold - CR 1/4 flying creature with Chromatic Spit of elemental damage

Older versions of D&D have types of Kobolds that use magic as well, which can be very dangerous when used with traditional warrior Kobolds in a pack.

Kobolds are often described as inventors and pack hunters, meaning they would never engage in a fight without a group. So, a bold DM might give their Kobolds a great strategy to hinder players, using traps and Pack Tactics to exploit weaknesses. Through Pack Tactics, Kobolds gain advantage on attacks when they are together, allowing them to succeed when swarming weaker targets.

Any Kobolds smart enough to ambush adventurers with traps are already a greater threat than they are usually perceived. By throwing in some swarming tactics or even the Kobolds using other monstrous pets to distract parties, these descendants of dragons in D&D's Monster Manual won't be taken lightly again.

4 Flameskulls Devastate Parties With Explosive Firepower

Just Cast Fireball

The Flameskull is an underrated Undead CR 4 monster whose biggest strength is simple - they can cast Fireball. These hovering balls of flaming skulls can hover with a 40ft flying speed, possessing immunity to nearly every status condition and several damage types, including Fire and Necrotic. With Magic Resistance as well, Flameskulls are potent guardians who are lethal when angered.

Flameskulls also have the ability to cast Magic Missile and Mage Hand, making them novice Evokers whose magic can cut throw character HP. With multiple Fire Rays dealing more Fire damage when they use up their one cast of Fireball, Flameskulls are designed to deal damage fast. Even if you destroy a Flameskull, it regenerates in 1 hour if players do not use Holy Water or Dispel Evil and Good to purify them.

3 Shadows Are TPK Experts Among Undead

Life-Drinking Shades Could Lurk Around Every Corner

For a long time, the Shadow CR 1/2 Undead has hit above its weight class, wiping out low-level parties with minimal effort. This is due to the creature's ridiculous damage resistances, which include:

• Acid
• Cold
• Lightning
• Fire
• Thunder
• Bludgeoning, Piercing, or Slashing that is Non-Magical

With additional immunities to Necrotic and Poison damage, Shadows are extremely hard to kill, despite their low health. Unless you have a source of Radiant damage to exploit its one vulnerability, your party will struggle against a group of Shadows. As of the 2024 Monster Manual, Shadows can even take a Bonus Action to Hide in dim light, making them even harder to track down and eliminate.

When Shadows attack, they are equally as threatening as they are on defense. One Shadow can use its Draining Swipe to deal Necrotic damage and lower a target's Strength score by 1d4, killing them if their Strength is reduced to 0. According to D&D's written rules for this creature, any Humanoid killed this way rises as another Shadow, creating an unstoppable army of undead creatures who seek to drain more life.

2 Corpses Are Created By Carrion Crawler Poison

Dungeon Scavenger Locks Down Targets For Its Next Meal

The Carrion Crawler received perhaps the most impactful change in the 2024 Monster Manual that turns a normal threat into an unexpected terror. This CR 2 creature is a ravenous corpse-eater, roaming around dungeons as segmented carnivorous worms. Ambushing adventurers by climbing onto surfaces and dropping from them, Carrion Crawlers have one trick that makes them far deadlier than parties can imagine.

When a Carrion Crawler uses its Paralyzing Tentacles to attack, it has a chance to Poison and Paralyze a creature with a single touch. For one failed Dexterity Saving Throw, a party member can be poisoned and stuck from doing anything on their turn. This alone makes Carrion Crawlers a nightmare, as all it takes is one bad roll to be at its mercy.

1 One Banshee Can Defeat Any Character Instantly

A Deadly Wail Scares The Soul Out Of Party

A variation of a Ghost, the Banshee is an Undead spirit whose very visage can Horrify characters into a Frightened state. However, the true danger of a Banshee comes from its Deathly Wail, which imposes a Constitution Saving Throw. On a failure, creatures who hear the Wail drop to 0 Hit Points, instantly forcing them to make Death Saving Throws or die permanently.

As of the 2024 Monster Manual, the Banshee's Deathly Wail has been nerfed slightly, only reducing a creature's HP to 0 if it had 25 or less Hit Points. That being said, this ability alone makes Banshees shockingly difficult.

Similar to the Shadow, a Banshee has a ton of damage resistances and immunities that make it hard to take down. With much higher health than a Shadow, this enemy is dangerous when faced alone, and downright apocalyptic to face when there is more than one. With Incorporeal Movement to go through walls and a sense for where anything living is located within a mile of it, there's no escaping an enraged Banshee either.

Although they can only use Deathly Wail once per day, having an attack that drops a character instantly can be quite a shock. The unexpected difficulty of a Banshee in Dungeons and Dragons can create a truly tense encounter that players will for a long time.