The Thing | New Monster for Fifth Edition

Like most of you, I’m a big fan of John Carpenter’s 1982 classic, The Thing. It’s the perfect blend of cosmic horror and absurdity and it’s still hella creepy even by today’s standards. So here is my take on the classic monster that appears in the movie for Dungeons & Dragons Fifth Edition.

The Thing

From Fandom’s entry on The Thing:

The Thing is an extremely hostile shape-shifting extraterrestrial organism and the primary antagonist of the 1982 science-fiction film The Thing, its prequel, video games, and literature. The Thing has the ability to assimilate other life forms in order to survive and spread. The original physical characteristics of The Thing and its motivations are unknown as it could have assimilated hundreds if not thousands of other species before it crashed on Earth.


The Thing

Large aberration (shapechanger), chaotic evil

Armor Class 13

Hit Points 65 (10d8 + 20)

Speed 30 ft., climb 30 ft.

Str 16 (+3)Dex 16 (+3)Con 17 (+3)Int 15 (+2)Wis 16 (+3)Cha 15 (+3)

Skills Deception +7, Perception +7, Stealth +5

Damage Resistances cold

Senses blindsight 30 ft., darkvision 60 ft., passive Perception 17

Languages the languages of the creatures it’s assimilated

Challenge Rating 4 (1,100 XP)

Shapechanger. The Thing can use its action to polymorph into a Small, Medium, or Large creature it has assimilated, or it can use its bonus action to transform back into its true amorphous form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.

Assimilate. A creature that touches or hits The Thing with a melee attack while within 5 feet of it must make a DC 13 Constitution saving throw or contract a disease-Thing assimilation. While infected, the target can’t regain hit points, and its hit point maximum is reduced by 4 (1d4 + 2) at the start of each of its turns. If the disease reduces the target’s hit point maximum to 0, the target instantly transforms into another Thing. Only a wish spell can reverse the transformation.

Regeneration. The Thing regains 10 hit points at the start of its turn. If it takes fire or radiant damage, this trait does not function at the start of its turn. The Thing is only destroyed if it starts its turn with 0 hit points and doesn’t regenerate.


Multiattack. The Thing makes two slam attacks.

Bite (True Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 10 (2d6 + 3) piercing damage or 17 (4d6 + 3) if The Thing is Large, and the target is subjected to The Thing’s assimilate trait.

Pseudopod (True Form Only). Melee Weapon Attack: +5 to hit, reach 15 ft., one creature. Hit: 5 (1d4 + 3) piercing damage or 8 (2d4 + 3) piercing damage if The Thing is Large, and the target is subjected to The Thing’s assimilate trait.

Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 3) bludgeoning damage or 12 (2d8 + 3) bludgeoning damage if The Thing is Large.

Attach. The thing makes a Pseudopod or Slam attack against a target it can see. If the attack hits, instead of dealing damage, The Thing attaches to the target, and the target must immediately make a saving throw against its Assimilate trait with disadvantage. While attached, The Thing doesn’t attack. Instead, at the start of each of the target’s turns, it must repeat its saving throw against The Thing’s Assimilate trait with disadvantage. If an attached target is infected with the Thing Assimilation disease, its hit point maximum is reduced by an additional 1d4 at the start of each of its turns.

The Thing can detach itself by spending 5 feet of its movement. It does so automatically if it takes fire damage or if a spell or effect that cures disease is cast upon the target.

Split. The Thing splits into two new Things if it has at least 10 hit points and its size is Medium or larger. Each new Thing has hit points and temporary hit equal to half the original Thing’s, rounded down.

Combine. A Small or Medium Thing can combine itself with another Small or Medium Thing within 5 feet of it. The target disappears and The Thing gains temporary hit points equal to the target’s remaining hit points. If The Thing gains temporary hit points equal to more than half its original hit point totals using this action, The Thing increases in size. Any equipment it is wearing or carrying is not transformed. While enlarged, The Thing is Large, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and makes Strength and Intelligence checks and saving throws with advantage. It also gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. If The Thing lacks the room to become Large, it attains the maximum size possible in the space available.

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This content is unofficial Fan Content permitted under the Fan Content Policy. Not approved/endorsed by Wizards. Portions of the materials used are property of Wizards of the Coast. ©Wizards of the Coast LLC.

1 thought on “The Thing | New Monster for Fifth Edition

  1. If the Creatrue described above was 10D8, all Attributes at LESS THAN 16, and had no more than one Attack for 1D8 damage maximum [or possibly 2 Attacks for 1D4 each], then it would be 10 EHD [which is to say, 10 Effective Hit Dice, with 1EHD being equal to 1D8], and it would thus score at CR 4. Each 3EHD above this value, due to greater HD, scrupulously totalled up abilities, etc., causes the CR value to increase by +1. The Creature described above has +26 EHD of additional abilities [many of them major, and thus worth +2 EHD each]. Thus, this qualifies it as being of CR 12 value. The damage per round output for the Creature alone is enough to put a single Level 4 Character on the deck, probably dead, from one attack. And this doesn’t allow for its Special Abilities, or its practical immunity to damage when being fought.

    For CR4, this Creature is fatally and cripplingly overpowered, as noted above..

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