Humans have long been fascinated by the wildwood—living in it’s vicinity was the source of tales about creatures ferocious and benign, friendly and hostile. As they started to settle deeper and deeper into the forests, respect for the unknown diminished. Lumber was gathered, stone abodes were built. As the pestilence that was humanity grew bigger, so did the forest’s and its inhabitants’ wrath.

Wrath of nature. At the heart of the forest lies a secret. In a place born of darkness and primeval nature, resides a mighty and terrifying guardian. Immune to human steel, it is believed the leshen is nature’s way of protecting the forest and the animals that live within it from the threat humans started to pose upon their ravaging expansion deeper into the lands. Sometimes called leshii or leszi, leshens are ancient and powerful forest spirits. Possessing a deer skull as a head and tree-like limbs, the sight of a leshen is a terrifying one. Villagers sighting one passing between trees will usually be clever enough to leave the woods at peace, a preferable fate than to risk the ire of the creature.

All seeing Watcher. A leshen will turn nature itself against those that trespass on his lands. They use their inborn magic to control the plants and animals within their territory — and so when stalking them, half the battle is merely getting near enough to strike. Animals, even timid and harmless ones, will be taken by a frenzy that will only stop with the death of the intruders, attacking on sight anyone they cross path with. Roots will sprout from the ground, trying to grapple, crush and strangle the unwary, burying them into deep earthy tombs, never to be seen again. Thankfully, it's difficult to unknowingly stumble into the territory of a leshen. The borders of its charge are warded with totems made of roots, stones, plants and animal bones, hanging from trees or stacked on mounds. One may also have to destroy a leshen's warding totems to rid a forest of its presence. The totems are the eyes and ears of the leshen throughout the forest and crossing or destroying one is a sure way to declare war on the creature. leshens are also known to be able to appear and disappear unexpectedly near their totems.

Primeval Keeper. Leshens are the herald of nature in many ways, sometimes worshipped, this creature can heal other woodland animals and fey, and are known to care for the ones left at their totems, even domestic pets. With time and efforts, a druids can work in collaboration with them if a leshen comes to recognize the druid as part of his forest. Some call them the Old Gods, and believe they were here before the divinities even existed. In some small and rural communities, especially the ones far from major trade routes and industrious cities, the leshen is the only god recognized by the villagers and the glade under his protection is considered sacred ground. Leshens found in this setting tend to be more lenient toward lost souls wandering into their land, giving them warning sign and trying to drive them off their territory instead of killing them outright.

Ancient Leshen:

Deep into the darkest forest, where no man has set foot in centuries, lurk the ancient leshen. These leshens remember the primal state of the world, when civilisation didn't exist and when the forest was covering most of the land. They were already old when dwarfs and elves were still young races. Untouched by time, leshens old enough to earn the appellation "ancient" wield greater powers and use advanced tactics that make them particularly dangerous.

Variant:

The Marking Some Leshen and Ancient Leshen can "mark" a humanoid living in the same region, leaving them alive and unhindered by the creature's magic until it needs to sap energy from them. This can allow the leshen to bring itself back to life after being slain. When it dies, the leshen can sap the life energy from its marked host, killing them and using their energy to rejuvenate. The only known way to prevent it is to kill the marked host before killing the leshen or to exile that person out of the leshen's territory. A leshen with this option has the following additional trait:

Rejuvenation. When the leshen is killed, if the humanoid it marked is alive and in the region of the leshen's lair, it starts to reform in the woods over the course of 1d10 days, regaining all its hit points and becoming active again. If both the leshen and the marked host are simultaneously dead, it can't rejuvenate.

leshen lives in deep forest, usually near a grove or a clearing with a large concentration of totems made of natural materials and animal bones.

Lair Actions

On initiative count 20 (losing initiative ties), the leshen takes a lair action to cause one of the following magical effects:

• Roots and plants burst out of the ground, grappling and lashing at creatures. The area within 60 feet around the leshen becomes difficult terrain until initiative count 20 on the next round. Huge or larger creatures are not affected.
• The leshen and allied creatures within 60 feet of the it are healed of 18 (4d8) hit points.
• A green mist fill the lair. All creatures within 60 feet of the leshen must succeed on a DC 18 Constitution saving throw, taking 13 (4d6) poison damage on a failed save, or half as much damage on a successful one.

Regional Effects

The region containing a leshen's lair is empowered by the creature's presence, creating the following magical effects:

• Beast creatures are empowered by the leshen's presence. Giant and Dire version of beasts creatures are more common here than anywhere else. Additionally Beast creatures within 6 miles of the lair that have an Intelligence score of 2 or lower are charmed by the leshen and are agressive toward intruders in the area.
• The leshen can alter the weather at will in a 6-mile radius centered on its lair. The effect is identical to the control weather spell.
• The totems of a leshen allow him to watch over his territory within 6 miles of its lair. The effect is similar to the arcane eye spell, but the eye cannot move away from the totem.

When the leshen dies, all of these regional effects fade over 1d10 days.