Tidecull Coral (Poison)

Uncommon, ingested, onset (2 minutes), cost 2,400 gp

The sea’s anger is unleashed and its victim’s lungs rapidly fill with seawater choking it to death. A creature takes 16 (4d8) cold damage as the water fills its lungs and makes a DC 18 Constitution saving throw when subjected to this poison. On a failure, it takes the damage again at the start of its next turn and makes the saving throw again. On a failure by 5 or more, the creature immediately drops to 0 hit points and is dying of suffocation . On a success, the effect of the poison ends.