Treant, Mangrove

Family: Treant

Huge plant, neutral

Armor Class 15 (natural armor)
Hit Points 136 (13d12 + 52)
Speed 30 ft.

20 (+5) 7 (-2) 19 (+4) 12 (+1) 15 (+2) 12 (+1)

Skills Athletics +8, Nature +4
Senses passive Perception 12
Languages Common, Draconic, Druidic, Sylvan
Challenge 7 (2,900 XP)


  • False Appearance. While the mangrove treant remains motionless, it is indistinguishable from an ordinary mangrove tree.
  • Grasping Roots. The treant has advantage on Strength and Dexterity saving throws made against effects that would force it prone.
  • Siege Monster. The mangrove treant deals double damage to objects and structures.
  • Tiny Spies. The mangrove treant can communicate with mosquitos as if they shared a language. The mosquitos alert the treant to the presence of intruders, and the treant has advantage on Wisdom (Perception) checks to notice creatures within 60 feet of it.


  • Multiattack. The mangrove treant makes two slam attacks.
  • Slam. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage.
  • Mangrove Mosquitos. The mangrove treant calls a swarm of mosquitos from its branches. The swarm of mosquitos uses the statistics of a swarm of insects, except it has a flying speed of 30 feet. The swarm acts an ally of the treant and obeys its spoken commands. The swarm remains for 1 day, until the treant dies, or until the treant dismisses it as a bonus action.


The treant can have only one swarm of mosquitos at a time. If it calls another, the previous swarm disperses.

Gnarled roots reaching deep into the muck act as legs for this group of trees conjoined into a sentient being.

Ancient Grove Guardians. Mangrove treants provide shelter and a resource-rich environment for many creatures. They extend their roots into the water, where several species of fish thrive. Biting and stinging insects, most notably mosquitos, dart about in cloud-like formations near the water’s surface. Arboreal animals nest high among the treants’ boughs mostly removed from the depredations of the insects. Unlike their forest cousins, these swampland treants are more concerned with the safety of those under their protection and less concerned with the overall health of the swamp. They decisively react to direct threats to themselves and the creatures within their boughs and roots, but they may not act if something endangers an area outside their immediate groves. Mangrove treants continue to grow throughout their extraordinarily long lives, which can reach millennia if they see no external disruptions. The treants also add ordinary mangrove trees into their gestalt, incorporating the trees’ ecosystems into its whole.

Friend to Lizardfolk. While a mangrove treant is generally wary of civilization, it befriends lizardfolk who show proper deference. Lizardfolk help control the treant’s fish population, since the treant normally doesn’t house predators, and they act as protectors to the treant. Various groups of lizardfolk venerate a mangrove treant as a respected elder or a being sacred to their deities. Some lizardfolk shamans know the secret to awakening a mangrove treant.

Mosquito Whisperer. A mangrove treant eventually learns to communicate with all the creatures inhabiting its grove, but it can always communicate with mosquitos. A dormant mangrove treant that is hosting mosquitos is rarely caught off guard thanks to diligent reporting from the insects. The treant can send mosquitos on reconnaissance missions, but the insects provide increasingly vague details the farther they travel from the treant, making them reliable spies only over short distances.

The treant also has a modicum of control over mosquitos. It typically exerts its will to keep the insects from overwhelming the animals living among its branches. When the treant faces a threat, though, it can call the mosquitos into a swarm to drive off or kill the threat.

Section 15: Copyright Notice

Tome of Beasts 2. © 2020 Open Design LLC; Authors Wolfgang Baur, Celeste Conowitch, Darrin Drader, James Introcaso, Philip Larwood, Jeff Lee, Kelly Pawlik, Brian Suskind, Mike Welham.

This is not the complete section 15 entry - see the full license for this page