By Alan McCoy from Dungeons & Dragons: Fundamentals
How to build challenging
encounters against a Corpse Flower
Note: This has been prepared utilizing the 5E Core Rules. The Corpse Flower can be found in the Mordenkainen’s Tome of Foes page 127.
The Corpse Flower is a Large animated plant that grows from the ground in which the corpse of an evil necromancer or powerful undead has been buried. These plants are a rare occurrence on the prime material plane, usually occurring only in lands that have been steeped in evil for generations or on planes of existence associated with evil.
The Corpse Flower will sprout from the grave in only a few days but will then spend several weeks growing and maturing prior to tearing itself from the ground to scavenge humanoid corpses that it uses to incorporate into its form. Using fibrous runners, the plant digs up once living material such as bones or other body parts that it uses to support to its ever-enlarging form, much like a lattice supports other less malicious plants such as grapes or tomatoes.
The sheer malevolence contained within the necromancer or former undead is what caused this creature to form, take root, and eventually become a murderous terror. This flower is rooted in evil and hates all life, it will do as much destruction as it can before it is destroyed.
If the plant is uprooted and burned as a seedling, potentially the ground upon which the undead or necromancer consecrated to a good aligned or at least not undead liking deity, the growth of the Corpse Flower can be prevented.
Initially smaller in size, the Corpse Flower will grow rapidly as it consumes more and more corpses. After reaching Large size, these plants will begin to release excess undead as zombies. As the plant has no control over the zombies, they will avoid releasing them until they are in a fight.
The Corpse Flower has a characteristic stench of death that carries the touch of the grave with it.
Step 1) Let’s Review what we know about
The Corpse Flower is a large mobile plant, that smells horribly and is often accompanied by a group of animated zombies, it can consume the dead to heal itself.
The Corpse Flower move or climb twenty feet per round.
The Corpse Flower has High Strength, Wisdom and Dexterity, Exceptional Constitution and poor Charisma and Intelligence.
The Corpse Flower has Blindsight 120-feet but is blind at ranges beyond this. It has a passive perception of 12.
The Corpse Flower is immune the conditions: Blinded and Deafened.
The Corpse Flower cannot speak and understands no languages.
Step 2) Determine the probable Strategy.
The Corpse Flower is unintelligent, and inexperienced in life, therefore it has no ability to form a strategy other than the drive to attack life, to consume, and to continue to survive.
The malevolence that brought this creature into existence provided it with some instructions on how to be an effective combatant. These include but are not limited to:
See a corpse, consume it.
GROW!
Step 3) Determine Tactics (see tips and observations below)
The Corpse Flower can grow quickly when the field of battle or graveyard it seeded it has plentiful corpses upon which to feed. Once it achieves full growth it will continue to consume, creating a mob of zombies that will follow it as it moves.
The zombie mob effectively expands the radius of the STENCH OF DEATH Ability from a 30 foot square (10 foot radius) to a potential 50-foot radius around the creature, though the actual positioning of the zombies will dictate the exact size and shape of the cloud.
The Corpse Flower can make three tentacle attacks that also cause poison damage. It will target those that are not moving and potentially incapacitated first, or those that are retching and potentially poisoned second.
The Corpse Flower can use a bonus attack to ingest a corpse, one of its zombie mob, or some other corpse on the field. This action heals it for 2d10 HP. If this brings its total to 190+, the Corpse Flower will extrude a zombie to join its mob.
Step 4) DM Tips and Observations
This creature like many of its type are best used when the Adventurers are in the “Kill the Monsters – Take the Treasure” mode. It demonstrates to them that there are consequences to their actions, potentially very serious ones.
A follower or minion that the creator has zero control over, is effectively a liability rather than a help to the creator. I would motivate the Zombies created by the Corpse Flower to follow or stay within twenty feet of the Stench of Death that the flower gives off.
While I normally agree with WotC and utilize the ‘Average Hit Point Total’ I would make this creature the exception, it has the ability to heal itself by consuming corpses, thus its completely reasonable, that it would have the maximum possible hit points (195). I would go further and state that when it consumes and “Heals” itself to over 190 HP, it extrudes a zombie follower.
I dislike throwing the condition INCAPACITATED around lightly. I propose that instead we increase the DC to 16 and a single failed save applies the POISONED condition, and a second failed save the INCAPACITATED condition. I absolutely hate the idea of conferring immunity to the stench for 24 hours after a successful save, I would instead allow a half-hour of immunity.
If the Corpse Flower has the strength and ability to swallow a corpse, then it also has the strength to swallow an incapacitated but living person as well. If you allow this, then I would probably apply:
BONUS ATTACK: DIGESTION +5 to HIT, Reach Zero. Damage 8d6 POISON. Note that if the target is incapacitated, then attacks are made at advantage and are automatically critical hits.