Thorn Elemental (Boss)

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Thorn Elemental (Boss)
Level 15 Boss NPC, Huge size (20 base)
30 speed
10 (4d8)
8 (3d8)
5 (2d6)
5 (2d6)
Hit Points
Boon Focus III (Regeneration)
Potent Bane (Immobile)
Multi-Bane Specialist (Forced Move & Immobile)
Boss Edge 5
Boon Focus I (Barrier)
Superior Concentration I
Favored Attacks
Smash (inflict damage): Might vs Guard
A heavy blow, like a tree falling on you. Knocks the target down if damage is dealt.
Entangle (inflict Forced Move & Immobile): Alteration vs Guard
A long root bursts from the ground to pull and ensnare the target
Reaching Vines (inflict Disarmed): Alteration vs Guard
Vines lash out from the elemental to snatch away sources of harm and entangle them on the elemental's back
Bramble Barbs (inflict Persistent Damage): Alteration vs Toughness
Creatures trapped within the vines brambles are torn at by vicious thorns, taking 1d10 bleeding
Favored Boons
Regrowth (invoke Regeneration):
The elemental draws on the power of nature to close over its wounds, healing 1d10 per round
Brambles (invoke Barrier):
A 25' square patch of brambles sprouts rapidly from the ground. The barrier is Damaging (1d10), Hindering, and Baneful (Persistent Damage). The Baneful property uses the "Bramble Barbs" attack.
Core Rules Compatible


The Thorn Elemental is a durable, high level boss that focuses on disrupting movement and outlasting its opponents. It can potentially force characters to spend multiple turns picking their way free of the brambles and is devastating if it is allowed to get into melee with a trapped character. At range, characters must have backup weapons or lose their effectiveness when their primary weapon is taken from them. The boss level given above is an estimate as it does not use the quick-build table, and it should be noted that high level parties vary hugely in effectiveness depending on factors like team composition, feats and extraordinary items. Use your judgement when including this NPC in your campaign.


Thorn was once a human, taken from their home by a mysterious organisation and promised superpowers. These powers came with a risk though, and Thorn's new ability to control plants also caused them to mutate into a plant themselves. Tossed out into the world as a failed experiment and with only the barest hint of sapience, Thorn was taken in by a villainous mercenary company who use it as their brutish trump card when they come up against superheroes. The Thorn Elemental is a generalised version of this NPC character from the author's game.

Alternate Options

The challenge of this boss can be significantly increased by increasing its Alteration score to 9 or 10. This will increase the damage of the barriers and also add the Obscuring property, which provides cover from ranged fire and makes assisting allies trapped within much more difficult. When facing an evasive party (using Teleport, Flight, Climbing, etc) or a party with many allies, some woodland animal or animated plant Summon Creatures can help level the playing field by occupying some characters while the elemental focuses on others.


The Thorn Elemental was originally used as a unique villain in a superheroes setting, but fits best in high fantasy as a wild nature spirit.

Character Build

Basic Information

Visual Description

An enormous mass of gnarled and spiky wood, that may or may not have a humanoid shape. As it moves, its many limbs tear up from the ground leaving behind broken roots, only to quickly bury themselves when they contact the earth again.


Plant elemental


Huge. 20' in all directions, and can grow longer in one dimension by shrinking in the other two.


Slow. The elemental only moves its full 30' if it absolutely has to, preferring to pull its prey back instead of chasing where possible. It is not hindered by rough terrain, but is slowed by half if it gets more than 10' from exposed earth.

Character Background

The thorn elemental is quite literally a force of nature. It will almost certainly have been known about among the nearby populace for generations, but can only be found if it wants to be found as it is happy spending most of its time pretending to be a particularly gnarly tree. It has subhuman intelligence but has grown wise to many tricks employed by those who have sought to kill it over the years. When threatened, it lashes out with incredible ferocity; this is no winsome dryad, but an old and terrible entity from the dark wood.

Goals, Instincts, Motivations


The elemental seeks to expel intruders from its realm, either the forest where it lives or the area where it currently stands.


The elemental fears fire but is too old to panic except under extraordinary circumstances, like the breath of an adult dragon. Its first instinct is always to entrap foes, and slowly wear them down until they can be pulled into the earth to nourish its roots. It is not intelligent, and will go after the most obvious target or the one which has caused it the most harm recently. Targets that are not harming it will mostly be ignored, but if a foe attempts to flee it will prioritise stopping them. It will undergo great effort to stop these intruders from leaving, but if any slip the net it will not pursue.


Revenge against those who dare harm it or trespass into its realm.



The elemental is slow, but immeasurably strong and its blows have significant weight behind them. In direct contexts of strength it will inevitably win unless it it beaten quickly, this could perhaps be represented by increasing advantage for the longer it is applying its strength to the same task.


This represents the elemental's control over plants and the environment. To fit the description of a thorny bramble, this attribute is additionally granted the Persistent Damage bane. This could instead be achieved by granting the elemental Entropy as well, and then access to other banes such as Sickened could increase the "dark woods" feeling of this creature.



This is a tough enemy that will keep going at nearly full strength even after taking significant damage, so it is given a very high hitpoint total. Along with Regenerate this will keep the thorn elemental fighting for longer than most bosses, especially if it does not fight alone. You may wish to increase or decrease this total based on the number of party members and how quickly you want combat to end.


This is relatively low for a boss. The elemental is made of living wood, which is not hard to harm even if it can sustain a lot of damage.


The elemental is an old force of growth, and so is resistant to poisons, bleeding, and many other forms of bodily harm.


The elemental is not intelligent or particularly mentally resilient, though you should consider whether any banes which target Resolve would in fact effect such an entity. For example, the elemental is unlikely to suffer Fear from mere mortals, and as a force of nature it can likely not be Charmed.


Boon Focus III (Regeneration)

The elemental is constantly regrowing its wooden flesh, and very few effects can disrupt this. Even if part of the creature is on fire, other parts may recover from damage. You could cancel this feat if a large enough inferno engulfs it.

Boon Focus I(Barrier)

Growing bramble patches is second nature to the thorn elemental. This feat also includes Multi-target Specialist V and Multi-target Expert, which are combined for simplicity.

Potent Bane (Immobile)

The roots and brambles with which the elemental entangles its foes are alive, and strong. When captured by these it is difficult to break free.

Superior Concentration I

The elemental can sustain two bramble patches simultaneously.

Multi-Bane Specialist (Forced Move & Immobile)

The same roots which entangle a foe also ensnare them. For gameplay purposes, the elemental has access to Forced Move at PL 8 within this move, even though it should only be able to use a maximum of PL 7 alongside Immobile.


The elemental can shrug off most attempts to slow it down. For banes inflicted with fire, instead roll to resist at disadvantage.

Boss Edge 5

This is a high level boss. It receives advantage 5 to all attacks and 5 additional boss actions per turn (separated by enemy turns where possible).

Favored Actions



Damaging attack, which also inflicts Knockdown due to the weight of the blow. This attack will rarely be used, unless an enemy is attacking it within its 20' reach. Remember advantage 5 from Boss Edge, and use multi-target attacks if the elemental is surrounded.


Inflict both Forced Move (20') and Immobile banes. The entangling roots aim to pull enemies into bramble patches and immobilise them there, or otherwise pull them closer to the elemental and then bring brambles up on top of them with its next action.

Reaching Vines

Inflict Disarmed. If a particular weapon is causing a lot of harm to the elemental, or if an enemy is still attacking while ensnared in brambles, it will attempt to snatch it away and store it on its body. If the elemental is far away, consider instead moving the weapon to a bramble patch.

Bramble Barbs

Inflict Persistent Damage (1d10). This is an attack for the Baneful property of the bramble barriers, made using the elemental's Alteration score.



Regeneration (1d10). This is always active, and invoked as a free action if cancelled. It can be cancelled by sufficient amount of fire (GM's call) or other extraordinary effects which would interfere with the growth of plants. The healing happens at the start of the elemental's turn, before any other effects such as Persistent Damage.


Barrier PL 7, Hindering, Damaging (1d10), Baneful (Persistent Damage). The Baneful property uses the Bramble Barbs attack, which triggers after the Damaging property has been resolved. Up to 2 25' bramble patches can be sustained simultaneously; the elemental will always maintain at least one, repositioning as needed.

Notes of Interest

During playtesting this boss struggled significantly against a character with Boon Focus II (Teleport) and a character with Invisible. Due to its low intelligence it was hard to justify it taking preventative measures against these tactics. Though its health is significantly higher than the quick-build suggested amount in addition to Boon Focus III (Regenerate), combat only lasted 5 rounds, with 2 of the 4 party members being out of action for 2 of those rounds.


Created by Sam Wilby for his Earth Shin Parahumans campaign on , session on Monday 17th of September 2018

License Notice

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