Medium fey (shapechanger), chaotic neutral

Armor Class 15 (natural armor)
Hit Points 85 (10d8 + 40)
Speed 30 ft., swim 40 ft.

8 (-1) 15 (+2) 18 (+4) 11 (+0) 13 (+1) 19 (+4)

Skills Deception +10, Perception +4, Persuasion +10
Condition Immunities charmed
Senses darkvision 60 ft., passive Perception 14
Languages Aquan, Common, Sylvan
Challenge 5 (1,800 XP)

Special Traits

  • Amphibious. The undine can breathe air and water.
  • Cursed Telepathy. The undine can communicate telepathically with any creature cursed by it with no range restriction. The undine doesn’t need to be on the same plane of existence as its cursed target to communicate this way.
  • Shapechanger. The undine can use its action to polymorph into a Small or Medium humanoid with legs or with a mermaid’s tail or back into its true watery humanoid form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.
  • Undine’s Curse. A creature cursed by the undine gains the Amphibious trait and a swimming speed of 30 feet. After each long rest, the target must succeed on a DC 15 Constitution saving throw or its Constitution score is reduced by 1d4 as it forgets to breathe regularly while resting. If the target received a Cursed Kiss from the undine within the past 24 hours, it automatically succeeds on its next saving throw. If the target ever lies to or is unfaithful to the undine, it has disadvantage on its next saving throw, and its Constitution is reduced by 2d4 instead of 1d4 on a failure. The curse lasts until the undine takes a bonus action to lift it or until lifted by a remove curse spell or similar magic.
  • Innate Spellcasting. The undine’s innate spellcasting ability is Charisma (spell save DC 15). The undine can innately cast the following spells, requiring only verbal components:


    • Multiattack. The undine uses its Cursed Kiss, if it can. It then makes two water hammer attacks.
    • Water Hammer. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage plus 10 (3d6) cold damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw or be cursed (see the Undine’s Curse trait).
    • Cursed Kiss (Recharge 5-6). The undine kisses a target within 5 feet of it. The target must make a DC 15 Constitution saving throw, taking 21 (6d6) psychic damage on a failed save, or half as much damage on a successful one. A willing target takes no damage but is immediately cursed (see the Undine’s Curse trait), if it wasn’t already.


Undines often use their charm and talent for illusion to draw mortals to them, wooing the mortal into a binding kiss in an attempt to gain an immortal soul.

Water Bonds. In many cases, undines befriend or partner with water elementals. The two communicate and share a single spirit, acting almost like a single creature. Some believe the undine devours or controls the elemental; others say the elemental worships and adores the undine willingly.

Section 15: Copyright Notice

Creature Codex. © 2018 Open Design LLC; Authors Wolfgang Baur, Dan Dillon, Richard Green, James Haeck, Chris Harris, Jeremy Hochhalter, James Introcaso, Chris Lockey, Shawn Merwin, and Jon Sawatsky.