Tidal Hags

When two sea hags wish to form a coven (see the "Hag Covens" sidebar in the SRD) without a third hag, they can undergo a ritual to bind themselves to the moon and become tidal hags. In this paired coven, one sea hag becomes the hag of high tide and the other becomes the hag of low tide, specializing to enhance their effectiveness together. This transformation heightens their bestial nature, perhaps sharing some cursed connection with lycanthropy.
       Hags of high tide feed off of violent desperation. Like a shark attracted to the thrashing of a drowning victim, they ferociously pursue hapless souls and glut on their misfortune with glee. Nothing sustains a hag of high tide more than witnessing pure dread, and they frequently act as messengers bearing tragic news.
       Hags of low tide are opportunistic creatures of greed and entropy in search of dark secrets, lost knowledge and obscure magic. Agelessly capitalizing on the exhaustive ebb and flow of nature, they seek out tragedy and play the sympathetic caretaker. Their victim, grateful for the doting of a compassionate granny, divulges one-too-many shameful memories or unknowingly binds themself to a contract, not expecting their words to be twisted against them. Amongst hags, those of low tide are master litigators, able to reason most anything out of a vague or innocently worded arrangement. When trickery fails, they are content to patiently erode the will of any who impede their covetous quest.
       Tidal hags might appear in the wake of a destructive flood, during a political upheaval, or amidst a terrible famine to spread further hopelessness and strike ill-favored deals with the desperate and immiserated. Their influence rises with the tide of despair, and when it subsides they slink away, clutching their plunder in withered, webbed claws.

Tidal Hag Lairs
Tidal hags live on the outskirts of civilization in coastal caverns, tidal flats, sunken ruins or the bloated corpses of beached whales. Their presence greatly exaggerates the fluctuation of the tides, attracts monstrous sea creatures and worsens storms.

Each tidal hag within a coven encountered in its lair has a challenge rating of 4 (1,100 XP).

Lair Actions
On initiative count 20 (losing initiative ties), the coven (hags within a coven share a single lair action per round) can take a lair action to cause one of the following effects, but can't use the same effect two rounds in a row:

• Until initiative count 20 on the next round, the hags can pass through solid walls, doors, ceilings, and floors as if the surfaces weren't there.
• A hag targets any number of doors and windows that she can see, causing each one to either open or close as she wishes. Closed doors can be magically locked (requiring a successful DC 20 Strength check to force open) until she chooses to make them unlocked, or until she uses this lair action again to open them.
• The tide suddenly rushes into the lair, flooding lower levels with water up to 10 feet deep. Each creature caught in the tide must succeed on a DC 13 Strength saving throw or take 4 (1d8) bludgeoning damage and be knocked prone. Tidal hags automatically succeed on the save. Hags of high tide within the lair gain 10 temporary hit points that disappear on initiative count 20 on the next round.
• The tide swiftly retreats, draining the lair entirely. Each creature caught in the tide must succeed on a DC 13 Strength saving throw or be knocked prone and pulled 15 feet along its course. Tidal hags automatically succeed on the save. Hags of low tide within the lair gain 10 temporary hit points that disappear on initiative count 20 on the next round.

Regional Effects
Each coven's lair is the source of three to five regional effects, including some that can directly harm intruders. These effects either end immediately if the hags die or abandon the lair, or take up to 2d10 days to fade away.

The region within 1 mile of a grandmother hag's lair is warped by the creature's fell magic, which creates one or more of the following effects:

• Birds, rodents, snakes, crabs, or snails are found in great profusion.
• Beasts that have an Intelligence score of 2 or lower are charmed by the hag and directed to be aggressive toward intruders in the area.
• Strange carved figurines, twig fetishes, or rag dolls magically appear in trees.

A powerful tidal hag creates one or more of the following additional regional effects within 1 mile of her lair:

• Tidal extremes are amplified, and occur at irregular intervals, causing coastal flooding at high tide and emptying to reveal the seafloor at low tide. Occasionally the tide arrives in shades of deep crimson, milky white or pitch black.
• Currents and tides are exceptionally strong and treacherous. Any ability check made to safely navigate or control a vessel moving through these waters has disadvantage.
• Shores are littered with dead, rotting fish. The hag can sense when one of the fish is handled and cause it to speak with her voice.