Leshy, Seaweed

Family: Leshy

Small plant, neutral

Armor Class 12 (armor)
Hit Points 26 (4d6+12)
Speed 20 ft., swim 20 ft.

10 (+0) 13 (+1) 16 (+3) 9 (-1) 15 (+2) 12 (+1)

Damage Resistances lightning, thunder
Skills Perception +4, Stealth +5, Survival +4
Senses darkvision 60 ft.; passive Perception 14
Languages Druidic, Sylvan
Challenge 1/4 (50 XP)

Special Traits

  • Air Cyst. Seaweed leshys constantly grow small bulbs filled with air. As an action, they can detach a bulb and give it to another creature. If consumed as an action, this air cyst grants the ability to breathe both air and water for 10 minutes. Seaweed leshys can have a maximum of four usable air cysts at any one time, and air cysts regrow at a rate of one per 24 hours.
  • Amphibious. A seaweed leshy breathes air and water.
  • Pass Without Trace. In areas of natural vegetation, a leshy can’t be tracked except by magical means. The leshy leaves behind no tracks or other traces of its passage.
  • Seaweed Speech. Seaweed leshys can communicate with seaweed, asking it about events within the past day, gaining information about creatures that have passed, weather, and other circumstances, within a radius of 30 feet.
  • Verdant Burst. When slain, a leshy explodes in a burst of fertile energies. All plant creatures within 30 feet of the slain leshy regain 6 (1d8+2) hit points, and seaweed quickly infests the area. If the terrain can support the growth of seaweed, the undergrowth is dense enough to make the region into difficult terrain for 24 hours, after which the plant life diminishes to a normal level; otherwise, the plant life has no significant effect on movement and withers and dies within an hour.


  • Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6+1) bludgeoning damage.
  • Water Jet. Ranged Weapon Attack: +3 to hit, range 30/60 ft., one target. Hit: 1 bludgeoning damage, and the target must make a DC 15 Constitution saving throw. On a failure, the target is blinded until the beginning of the leshy‘s next turn.
  • Change Shape. The seaweed leshy can take the shape of seaweed or return to its normal form. In seaweed form it is not capable of any other actions but is aware of its surroundings. It is otherwise indistinguishable from ordinary seaweed. Any items it carries fall to the ground when it becomes seaweed, but when it returns to its normal form it easily dons its armor at the same time.
  • Seaweed. Grasping seaweed sprouts from the ground in a 20-foot square starting from a point within 90 feet that is in saltwater. For 1 minute, the seaweed turns the ground and water in the area into difficult terrain. A creature in the area when the leshy uses seaweed must succeed on a DC 12 Strength saving throw or be restrained by the entangling seaweed until the spell ends. A creature restrained by the seaweed can use its action to make a Strength check against the same DC. On a success, it frees itself. After 1 minute, the conjured seaweed wilts away.


Seaweed leshies usually dwell along coastlines, happily splashing and playing in tide pools, but they are equally at home at sea, floating among large kelp beds. Although perfectly capable of existing out of water indefinitely, seaweed leshies prefer to limit their time away from the sea almost out of a sense of pride. Most seaweed leshies take a dim view of freshwater plant life, to the point of mocking such plants in the same way an urbanite might talk down to folk who live in more rural areas. Rumors of freshwater leshies are a sure way to bring peals of mocking laughter from a seaweed leshy.

Seaweed leshies resemble miniature, waterlogged green humans grown from leafy green seaweed, with skinny arms and legs, webbed hands and feet, and long strands of brown, green, or red seaweed for hair. They wear armor made from a pair of large clam shells or from several smaller shells tied together. This armor functions for a seaweed leshy, but not for any other creature.

Patient and thoughtful by inclination (save for matters associated with those silly freshwater leshies), seaweed leshies believe that in time nature brings what is needed by the ebb and flow of the tide or the steady flow of the river. They counsel against hasty decisions and rash actions, always preferring to wait and see what another day might bring.

Guardians of Plant Life. Originally grown as servants for more powerful fey and intelligent plant life such as elder treants, leshies are sentient plants who look after their unintelligent brethren and serve as nature’s verdant watchers. Several breeds of leshy exist, each being kindred to a broad group of plants or fungi. Leshies begin their existence as sentient though bodiless spirits of nature of the sort contacted by spells such as commune with nature. These spirits normally have no way to directly manipulate the physical world, but a skilled spellcaster (typically a druid) can grow a special plant body for one of these spirits, giving the spirit a home to animate.

Embodied Spirits. Once accepted into a body, a leshy’s spirit remains within unless the body is destroyed. Leshies do not fear death as many other creatures do, knowing that should they fall, their spirits merely return to the natural world and can be called to inhabit a new leshy body at some point in the future. As a leshy’s body dies, the magic animating it unravels in a burst of life energy that infuses its surrounding and quickens the growth of any plants in the vicinity. Some leshies even voluntarily discorporate to save the lives of ailing plants, knowing that their sacrifice may mean the continuation of countless otherwise helpless flora. Regardless of how a leshy dies, leaving the body traumatizes the spirit, and the leshy retains only faint memories of past corporeal existences.

Leshy spirits need not return to the same form if bound again to a body. Throughout its existence, a single spirit can inhabit any number of different types of leshies. A leshy without a body has no power to affect or contact the material world.

Unique. The rites and special materials required to create a leshy’s physical form vary between individual leshies.

Once the creator assembles the necessary materials, a leshy must typically be grown in an area of natural power, such as a treant’s grove, a druidic circle, or a site of pristine natural wonder. A newly born leshy is a free-willed, neutral being, under no obligation to serve its creator.

Section 15: Copyright Notice

Sea Monsters (5E) © 2021, Legendary Games; Authors Michael Ritter, Michael “solomani” Mifsud, Robert J. Grady, Mark Hart, Jeff Ibach, Alex Riggs, Scott D. Young, Jeff Lee, Matt Kimmel, and Jason Nelson.

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