Circle of the Undergrowth

Druids in the Circle of the Undergrowth are taught from a young age to observe and learn from the world around you. In particular, these druids focus upon the smaller plants that lack the bulk of the massive trees, or the propagation of more common plants such as weeds, the plants that have had to rely upon their own more unique approaches. Combat is where the Circle of the Undergrowth puts their knowledge into practice, using their borrowed tricks to attack in unconventional ways. 

Botanic Transformation

Beginning at 2nd level, you can use your bonus action to expend a use of your Wild Shape feature in order to emulate an aspect of the undergrowth. Whenever you use this feature, you gain a number of temporary hit points equal to 5 times your druid level and transform into one of the following options. These temporary hit points last for one hour.

The transformation lasts for one hour, until you lose all these temporary hit points, or until you use your Wild Shape again. If the transformations grants you access to a natural weapon, and you can use your Wisdom modifier instead of Strength for the attack and damage rolls using that weapon

Briar Form: Prickly branches and rough leaves emerge from your skin, covering your body. When a creature hits you with an attack while within 5 feet of you,  you deal 1d10 piercing damage to it. In addition, sharp thorns cover your hands, dealing 1d10 piercing damage on a hit. 

Vine Form:  Long prehensile vines sprout around you, wrapping you in a coat of green. While transformed, you have a climbing speed of 40 feet and can climb on difficult terrains or ceilings at will. You can also command these vines to lash out, acting as a reach weapon that deals 1d8 bludgeoning damage on a hit. 

Carnivore form: Numerous stems, thick with sweet sticky nectar,  grow from your pores, while your hands become flatter and your fingers long and sharp. While transformed, you can use your Wisdom modifier instead of your Strength modifier when making athletics checks. As a bonus action, you can have your tendrils swarm around any creature you've grappled, making a melee spell attack against them that deals 2d6 acid damage. 

 

Photosynthesis

Beginning at 2nd level, you can have learned to draw power from the sun into yourself. You gain resistance to radiant damage, and if you take radiant damage, you can use your reaction to gain immunity to radiant damage for one and turn and gain a number of hit points equal to half your druid level. You can use this ability a number of times equal to your Wisdom modifier (minimum of 1).

 

Homicidal Germination

Beginning at 6th level, all weapons granted to you by your botanic transformations are considered magical for the purposes of overcoming immunities and resistances. In addition, your study of the undergrowth has yielded greater understanding of its potential, allowing you to eke out greater performance from your transformations. You gain the following features.

Reinforced Epidermis: Your thorns and stems grow thicker around you. While transformed into your Briar form, you gain a +1 bonus to your AC. In addition, whenever you attack with your thorns, you may make an additional attack as part of the Attack action. 

Roothair Rampage: You become more aware of the sensitivities of your vines, allowing you to glean information from them. While transformed into your Vine form, you gain tremorsense with a range of 20 feet. In addition, you can attack with your vines as a bonus action. If you do so, you can't attack with it as an action. 

Sweetening Sap: You learn more of the tricks and trades of the flycatchers. While transformed into your Carnivore form, you get to target one creature within 60 feet of you as an action. The target must succeed on a wisdom saving throw or be charmed by you for one minute. While charmed in this way, the creature must use all of its movement to get close to you. The charmed creature won't move into obviously harmful terrain, but will take opportunity attacks to move closer. The target can make another saving throw at the end of its turn. If a creature reaches you, you may attempt to grapple it as a reaction. You can use this feature a number of times equal to your Wisdom modifier (minimum of 1). You regain all uses on a long rest. 

Accelerated Maturation

Beginning at 10th level, your Botanic Transformation has matured beyond its initial state into its adult form, and has granted you new power.

Prickly Deterrent: While transformed into your Briar Form, you can extend your thorns past yourself to form barriers. As a bonus action, you may make 2 10 foot high, 10 foot long, 5 foot deep barriers of tangled vines and thorns, originating from you in any direction. A creature can move through the wall, albeit slowly and painfully. For every 1 foot a creature moves through the wall, it must spend 3 feet of movement. Furthermore, the first time a creature enters the wall on a turn or ends its turn there, the creature must make a dexterity saving throw. It takes 4d6 slashing damage on a failed save, or half as much on a successful save. The walls vanish at the start of your next turn or if you move more than 5 feet after creating them.

Agricultural Omnipresence: While transformed into your Vine form, the ground around you in a radius of 30 feet is difficult terrain to hostile creatures. In addition, you may cast spells or make attacks as if you were present at any point within that radius. 

Gluttonous Allure: While transformed into your Carnivore form, your size is Large, and you no longer need to use your limbs to grapple. You have no limit as to how many creatures you can grapple at once. In addition, when you use your Sweetening Sap action, you can target a number of creatures equal to one fifth of your druid level, rounded down. You also now deal 4d6 acid damage to all grappled creatures.

Overgrowth

At 14th level, you have managed to pry the ways of life from plants. If there's one thing the history of evolution has taught us, it's that life will not be contained. Life breaks free, it expands to new territories, and crashes through barriers painfully, maybe even dangerously, but one thing is certain: You will find a way. 

You gain the following features. Once you use any of them, you cannot use any of the below features until you finish a long rest.

Root Penetration: You force one creature within 10 feet of you to make a Dexterity saving throw against your spell DC. On a failure, the creature takes 10d10 piercing damage and is restrained for one minute as a massive branch covered with thorns erupts from your hand and impales them. On a successful save, they take half damage and are not restrained. At the end of the creatures turn, it can make a Strength Saving throw to remove themselves from this branch and stop being restrained. If they fail this saving throw, they take 2d10 piercing damage as their flailing embeds the thorns further into their flesh.

Tumultuous Growth: The vines beneath your feet flail and lash with fury. All creatures of your choice within a 30 foot radius are moved 10 feet in a random direction and must make a Dexterity saving throw. On a failure, they are knocked prone and take 8d8 bludgeoning damage. On a success, they take half damage and are not knocked prone.

Fly trap: A titanic green jaw emerges from the ground, around a point you choose within 120 feet, snapping shut. All creatures in a 40 foot radius sphere around the point must make a Dexterity saving throw or take 3d12 piercing damage and 3d12 acid damage, as well as 2d12 acid damage at the end of their next turn, and be pulled 30 feet towards the center. On a successful save, they take half of the initial damage and are not pulled.  Flying creatures have disadvantage on this save.