Since 1974, players have traversed the unbridled and fantastical world of Dungeons & Dragons. The franchise has worked tirelessly to produce an ever-expanding library of magical creations. D&D has introduced many interesting elements from spellcasting to player classes yet the most impressive by far are its monsters.
Monsters act as a hindrance to players yet high-level adversaries have the potential to annihilate players regardless of level. These challenging beasts hold immense power capable of bringing widespread destruction in their wake. Even so, many high-level monsters stand well above others. These near-invincible monstrosities can wipe out parties and inspire worldwide devastation.
10 Retriever - Challenge: 11
Retrievers are mechanical servants of the Drow with the sole purpose of tracking and capturing targets. These demonic constructs carry out their master's quarry with natural precision and efficiency. Even though Retrievers possess no phenomenal attacks or powers their innate ability to track, and retrieve is unlike any other.
They can track any being or object that their master has seen, knowing its general direction and distance away. While seemingly unimpressive compared to other high-level monsters, Retrievers will always have an advantage against players. If they are on the same plane as the party, Retrievers can easily stalk, ambush, and defend against them without fail.
9 Mummy Lord - Challenge: 15
An immortal and sinister being, the Mummy Lord is among D&D's most powerful undead monsters. This undying ruler is a relentless adversary that proves to be challenging even outside its tomb or lair. The Mummy Lord's expansive list of attacks and abilities allow it to debilitate players effectively removing them from combat.
Using its wide selection of actions, it can easily manipulate battle and even resurrect itself upon death. Boasting proficiency in spellcasting and innate magical power the Mummy Lord can perform a variety of effects. It may impose a limiting debuff or even an everlasting curse on players. Even if the Mummy Lord succumbs to a party, it will revitalize itself within 24 hours if its heart is intact.
8 Devourer - Challenge: 11
Devourers are unyielding abominations of Orcus with the sole purpose of extinguishing all life. These torturous monstrosities torment mortals with the intent of consuming their bodies and soul. Upon entering the Material Plane, Devourers begin hunting for living beings to consume and enlist in their undead armies.
After bringing foes close to death, a Devourer entraps them in its ribcage and tortures them before they expire. While in its ribcage victims endure relentless suffering until death. If a player dies within its ribcage - a likely occurrence - the Devourer turns them into an undead depending on their power. This way a Devourer can dwindle a party and its allies while bolstering its forces.
7 Beholder - Challenge: 14
Beholders are among D&D's most notable monsters for their arrogance and otherworldly lethality. These self-serving aberrations are spiteful foes that are challenging to players even when faced outside their lair. A Beholder's eye rays unleash a flurry of attacks capable of imposing a random effect upon players.
Using its eye rays, it can weaken party members or even kill them instantaneously. Although the effects are random the Beholder can launch three attacks upon one target or three. This allows it to effectively ensure a player's demise or cripple most of the party providing it a significant advantage. Should the Beholder be in its lair or have underlings defeating it may become an impossibility.
6 Elder Brain - Challenge: 14
A hivemind and leader of the illithid colony, the Elder Brain is among D&D's most powerful psionic beings. This psychic monstrosity is ruthless and calculating providing parties with a less combative encounter. While the Elder Brain alone is ineffective in battle with servants under its guidance it becomes nearly untouchable.
Using its psionic abilities, it may infiltrate the minds of others or dictate the actions of its subordinates. The Elder Brain possesses a variety of abilities meant to control targets or damage them. Moreover, it can control those under its psychic link to attack, defend, or even sacrifice themselves. So long as the Elder Brain has capable servants it can unleash overwhelming assaults with little risk.
5 Dracolich - Challenge: 17
Both a dragon and an undead, the Dracolich is a frightening and powerful combination. Through a similar process used to create a lich, dragons can bind their souls to a phylactery becoming undead and immortal. While the dragon retains many of its previous features, it becomes exceedingly malevolent and exceptionally cunning.
Even though most evil dragons are nefarious and deceptive a Dracolich is far more covert in its plight for domination. Instead of blatantly furthering its goals a Dracolich will manipulate others in secret. Thus, hindering a party without endangering itself making it a truly elusive foe. Even if players discover a Dracolich, it will undoubtedly have the information/resources needed to combat them.
4 Purple Worm - Challenge: 12
A gargantuan and poisonous monstrosity, the Purple Worm is among D&D's largest and deadliest creatures. This subterranean beast traverses underground in search of unsuspecting prey above. Although the Purple Worm bears no powerful or complex abilities it can weaken and dispatch players effortlessly.
Using its massive mouth, it can entrap players and slowly digest them. Those unfortunate enough to face the Purple Worm head-on will risk being eaten alive. While it is possible to escape its bowels, it requires not only a great deal of damage but luck as well. However, if a player escapes, they will likely be weak enough for the Purple Worm to finish them off.
3 Nightwalker - Challenge: 20
Nightwalkers are born when a creature crosses into the Negative Plane and, surprisingly, survives. These dark and deadly beings are unwilling to serve mortals and only wish to end all life. While Nightwalkers rarely appear, it takes only one to bring the extinction of all living things on the Material Plane.
Simply being in their presence is harmful to life as it radiates death and almost entirely ensures that death is permanent. Nightwalkers have an aura that radiates death allowing them to effortlessly dispatch living things. Moreover, damage from Nightwalkers results in death only reversible through a Wish. Even if a party has Wish chances are more than one player will succumb to the Nightwalkers.
2 Marut - Challenge: 15
An accurate and relentless attacker, the Marut is - if not one of - D&D's deadliest constructs. These cosmic mechanical beings carry out and enforce written agreements on an extraplanar level. Should a party encounter these lumbering machines they will face their unbridled yet precise flurry of attacks.
Not only are Maruts impossibly exact in their assault but they are unchangeable as well. Using their fists or arcane energy, Maruts can automatically hit most targets regardless of their Armor Class. Parties, unfortunately, cannot change Marut's form meaning that spells like Polymorph are ineffective. Meaning, that players must face this seemingly indestructible machine without exploitations.
1 Tarrasque - Challenge: 30
The Tarrasque is a gargantuan beast capable of unleashing untold amounts of devastation. This impossibly titanic creature is so incredibly destructive that many view it as a bringer of the end times. While the Tarrasque is more than capable of inspiring an apocalypse, it is only awake for weeks or months. However, it will devour villages, destroy cities, and leave continents in ruin during this time.
Instead of facing the Tarrasque, many would rather avoid its path of destruction while heroes fend off its approach. Although with its near-impenetrable carapace and overwhelming size, defeating it is almost entirely impossible through normal means. Typically, players would need siege weapons to merely dent the gargantuan beast's defenses. Even if a party successfully defeats the Tarrasque, it is a force of nature and will ultimately return regardless.